A TREK THROUGH ELDORADO CANYON
Trip Leader - Beth Simmons
This field trip, a journey through geologic and human history, probably will encounter some obstacles. The first is traffic into
Eldorado Springs Canyon on a hot summer day. So the group will meet at the Eldorado Country Store at the intersection of Rt. 93 and
170. We will proceed eastward along the Eldorado Road to the Mesa Trail head Parking Area from where we will carpool into the park.
The meeting spot is an old time convenience store, one of few in the area. Here you can purchase soft drinks and copies of Joanna
Sampson’s book, “High, Wild, and Handsome.” The high spot is the south valley wall of South Boulder Creek that comes from the
mountains through Eldorado Canyon and spills out onto piedmont at the edge of the hogback to the west. The stream heads on the north
side of James Peak west of the Moffat Tunnel. It flows through “Mammoth Park” or “Middle Boulder Park,“ past the old ghost town of
Tolland, into its canyon at Rollinsville. The railroad goes along the creek in its upper reaches, on its way to the Moffat Tunnel. Before
construction of the Moffat Tunnel, there was a wagon road here that predated the present railroad. The Rollins Road followed the old
wagon road up across Rollins Pass and over the Continental Divide. Then came the Moffat Line. Gross Reservoir, a Denver Water Board
facility, dams South Boulder Creek along its course, west of Coal Creek Canyon, before the stream cuts its way through the Precambrian
Rocks of the Front Range into beautiful Eldorado Canyon.
Looking over the valley, you can see many stream terraces, levels left when the stream flowed at higher levels in the ‘more recent
past,’ called the Pleistocene. The cliff across the road exposes the Fox Hills Sandstone, the Cretaceous beach sand that marked the retreat
of the Western Interior Seaway. Under the Fox Hills is the Pierre Shale, much of which has been faulted out in this section.
0.0 Drive west along Eldorado Springs Road. Be wary of bikers. The road passes by the Fox Hills Sandstone on the south into the
South Boulder Creek Valley. It parallels the edge of the valley wall, following the old railroad spur grade to Eldorado Springs, with new
houses set high on the slopes to the south. Older houses line the road on the valley side. The water supplies in this valley approached dry
during the drought of 2002.
1.4
EDS Fire Department – the first calls for climber rescues come in here.
0.4 Mesa Trail Head on North, Dowdy Draw Trailhead on south. Turn into Mesa Trail Head lot on the south (Left). Leave some
cars parked here. Consolidate As MUCH as Possible.
Return to Eldorado Springs Road. Turn west. When we return we will walk to the old Dunn two-story stone ranch house. This was
the second home of the original settlers in this valley who came in 1860. This was NOT a road to the gold mines, but rather an agricultural
district where hay, cattle, and crops grew that provided the miners and settlers with much needed farm products. In 1862, the Dowdy
(Doughty) family operated first true American flour mill in Colorado Territory here, using a grindstone made of “local conglomerate.”
Eventually the Dowdys moved their operation to Boulder and then to Larimer County.
0.9
Pleistocene alluvium exposed in road cut.
0.1 Historic Eldorado Springs sign. Gate into Eldorado Springs. The gate crosses the Dakota Sandstone hogback.
ROUGH ROAD. GO VERY SLOW (THEY GIVE YOU NO CHOICE)
0.2 Eldorado Springs buildings on north side of creek. Ike and Mamie Eisenhower spent their honeymoon here in 1916. The
temperature of the springs is either 77°F or 82°, depending on which reference you read, but are only just warm by Idaho Springs
standards. They flow at the rate of 10-15 gallons per minute. There are four springs: Curie, Cave, Bath, and Arapahoe, which used to be
called the Boulder Radium Springs and Moffat Pool Spring. The water issues from much-faulted marl of the Cretaceous Niobrara
Formation. The heat is furnished by buried igneous rocks of Tertiary age, similar to the pegmatite dikes and rhyolite porphyries and the
Cretaceous basaltic flows at Golden. The resort is open from June to November.
Enter Eldorado Canyon State Park. $5 per car (it went up again) (more expensive than other state parks… can Boulder people
pay more, or are they just expected to?)
0.1
Turn left into park. Pay Money. Take left fork up hill toward new visitor’s center.
The tollgate sits in the Lyons Sandstone Hogback. The Lyons Sandstone is an ancient sand dune deposit which flanked the edge of
the Ancestral Rockies. An ancient seaway lapped along the east shores. The region probably looked like the area around the Sea of
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Cortez in Mexico today. In these sandstones (at least those from near Lyons) are the tracks of ancient proto-mammals and other animals
that had managed to escape the ocean environment. Notice the distinct perpendicular fracture patterns of the sandstone.
Notice the landslide/rockslide on the south side of the parking. Do not pull out the rocks at the bottom!
New Brick Restrooms. We will forego them for the even newer restrooms at the visitor’s center.
Near the brick restroom on the south side of the road is the contact between the Permian Lyons Sandstone and the underlying
Pennsylvanian Fountain Formation.
The BASTILLE is a world famous rock-climbing site. (Watch for falling humans!) The Fountain Formation, arkosic sandstone, is a
tough stone with lots of toeholds. It is better cemented here than at Red Rocks, where rock climbing is forbidden, and much tougher that
at The Garden of the Gods where a balanced rock barely survives.
As you reach out and touch the Fountain (one of the few outcrops where you can collect and never open the car door! But,
remember we’re in a state park) notice the immense variability in color and grain sizes within the rock unit. The Fountain here was one
of eleven alluvial deposits that came down an ancestral South Boulder Creek from the Ancestral Rocky Mountains during the late
Pennsylvanian Period. It is age equivalent to Red Rocks, Roxborough Park, and the Garden of the Gods, but these fans and the Flat Irons
in Boulder WERE NOT connected by one stream.
0.2
STOP 1. Harmon Waterfall on north side. Parking at Eagle Rock for photos.
0.1
Rockslide on south wall of canyon. This is called colluvium because only the force of gravity is working on this rock pile. Again,
please do not remove the rocks on the bottom!
0.1
Trailhead
The valley cuts along a fault contact here between the Fountain Formation and a Precambrian quartz monzonite\ younger than the
Boulder Creek Granodiorite, which is dated at 1.4 billion years. The monzonite, a granular plutonic rock containing approximately equal
amounts of orthoclase and plagioclase, thus intermediate between syenite and diorite, is tan to gray, fine-grained with scattered biotite and
muscovite flakes. It weathers to a pinkish-gray. The quartz content exceeds 2% by volume. This rock also contains microcline and
plagioclase feldspar and biotite and muscovite micas.
We will hike back to this spot after brunch. The quartzite is very well cemented together and will tear anyone’s pants. There are
garnets throughout the formation.
0.1
Turn just before the bridge and take the left fork into the south picnic grounds.
STOP 2. BREAKFAST BRUNCH STOP. This is the most pleasant part of the trip. Get out the food and EAT.
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Examine the rocks, if you are in the south picnic grounds, along the road cut for lots of garnets in the metamorphic sequence. If we
are near the visitor’s center, make sure to visit the restrooms and the displays. Purchase or donate a dollar or two for a copy of Joanna
Sampson’s “History of Eldorado Canyon.”
Trivia question -WHO WAS IVY BALDWIN?
After eating and clean up – Walk to the roadcut
0.1
Bridge. Notice the banding and garnets in the quartzite. Note pin cherry trees.
Return to vehicles. Turn right on return trip.
0.1 One lane roadcut
There was to be an extension of the railroad spur into the canyon to bring tourists to the dance pavilion and roller-skating rink and to
the base of the funicular that climbed the south wall up to the Crags Hotel and Resort. The railroad was never completed.
0.2 Contact at brick restroom between Fountain Formation and Lyons Sandstone.
Look for old dance pavilion up on rock ledge at 11:00.
Irrigation ditch on south side of creek. The ditches here are some of the oldest in the state, providing water for farms
downstream.Niobrara limestone somewhere in valley. Dakota Formation middle to edge of town.
0.3
Pavement (aren’t you glad?) Eldorado Springs apparently has set the record for speed holes!
1.0
Dowdy Draw Parking area on right, Mesa Trail Head on left. Retrieve cars.
Pull out of parking lot. Turn left.
Fox Hills Sandstone in roadcuts on right.
0.1
Intersection with CO 93. Cross 93 on CO 170, Marshall Road. Bear left.
0.2
Intersection. Old Marshall Road from Denver to Boulder is just ahead, but turn right on CO 170.
Fox Hill Sandstone in road cut west of intersection.
Laramie Sandstone in railroad cut. Exposed coal layers.
Look for two old railroad beds that cross the lowlands here.
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0.3
Note Lyons Sandstone used in wall on north side of road. The small long building behind the wall was the company store for the
Marshall Mine. It is pictured in its original state in Joanna Sampson’s Walk through History on Marshall Mesa. Check for copies at the
trailhead at Marshall Mesa.
Walk through History on Marshall Mesa is also available online at: http://web.ccd.edu/simmonse/marshall/index.html
0.2
Marshall Mesa Trail Head. STOP 3. Park here.
Walk up the trail, observing relics of the coalmines and railroads.
Cross Ditch – ‘Slack Ditch’ – recognized as man-made wetlands over 100 years. It dried up in 2002.
Ascend railroad grade.
Look across the valley to the north side of the road. There are a series of rectangular holes, each about the size of a large room in a
house. These collapse features are mine subsidence into the old shafts and tunnels.
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A TREK THORUGH THE COAL FIELDS
GEOLOGY OF FRONT RANGE COAL
The Lafayette/Louisville/Superior/Erie region of Boulder and Weld Counties fall within the “Northern Colorado Coal Field”. The
coal bearing layers are in the Laramie Formation, ancient tidal flat deposits on the edge of the waning Western Interior Seaway.
Triceratops and its adversary, Tyrannosaurus rex, ruled the swamplands where organic rich layers alternated with clay and mud. Time?
75 million years ago, during the Late Cretaceous
Era.
The sea vanished into the region we call
the Gulf of Mexico and the sediments became
rocks. When the Rocky Mountains uplifted 65
million years ago, the rock layers were tilted and
faulted. The coal layers, initially irregular,
became a maze of black stripes trapped and
broken between gray sandstones, claystones, and
the bright yellow sandstone of the beach deposit
called the Fox Hills sandstone.
Figure 1. Stratigraphic section of Marshall
area. [What is the reference for this section?]
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Map 1. Map of faults of coalfield [Proper credit should be given to whover constructed this map by way of a reference.]
Marshall
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ORIGINAL STRATIGRAPHIC MEASURED SECTION By Hayden
Cited in the 1871 Rocky Mountain Directory and Colorado Gazetteer, p. 75, 76
48. Drab clay with iron ore along the top of the ridge
47. Sandstone
46. Drab clay and iron ore
45. Coal (No. 11) no development
44. Drab clay
43. Sandstone, 15 to 20 feet
42. Drab clay and iron ore
41. Coal (No. 10) no development
40. Yellowish drab clay, 4 feet
39. Sandstone, 20 feet
38. Drab clay full of the finest quality of iron ore, 15 feet
37. Thin layer of sandstone
36. Coal (No. 9) nearly vertical where it has been worked, 12 feet
35. Arenaceous clay, 2 feet
34. Drab clay, 3 feet
33. Sandstone, 5 feet; then a heavy seam of iron ore; then 3 feet of drab clay, then 5 feet sandstone
32. Coal (No. 8) 4 feet
31. Drab clay
30. Sandstone, 25 to 40 feet
29. Drab clay, 6 feet
28. Coal (No. 7) 6 feet
27. Drab clay, 5 feet
These beds dip 37°
26. Sandstone, with a seam of clay, 12 to 18 inches, intercalated
25. Drab clay, 4 feet
24. Coal (No. 6) in two seams, 4 ½ feet
23. Drab clay, 3 to 4 feet
22. Yellowish, fine-grained sandstone in thin loose layers, with plants, 5 to 10 feet
These rocks dip 8°, entire sequence is 15 feet thick
21. Drab clay, excellent iron ore
20. Coal (No. 5) 7 feet
19. Drab clay
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18. Sandstone, dip 11°. This sandstone has a reddish tinge, and is less massive than 14.
This sequence is 20 feet thick, obscure
17. Drab clay
16. Coal (No. 4)
15. Drab clay
14. Sandstone, massive, 60 feet
13. Drab clay
12. Sandstone
11. Drab clay
10. Coal (No. 3)
9. Drab clay
8. Sandstone, 25 feet
7. Drab clay.
6. Coal (No. 2) 8 feet
5. Drab clay
4. Sandstone, about 25 feet
3. Drab, fire clay, 4 feet
2. Coal (No. 1) 11 to 14 feet
1. Sandstone
In bed No. 23 there are three layers of sandstone which contain a great variety of impressions of leaves. Below coal bed, No. 6
there is a bed of drab clay, seven feet thick, with a three-foot thick coal seam at the outcrop; but the coal appears to give out or pass
into clay as the bank is entered, so that there are ten feet of clay above coal bed No. 6.
Much of the iron is full of impressions of leaves in fragments, stems, grass, etc. The ore is mostly concretionary, but
sometimes it is continuousenough to give the idea of a permanent bed. There are several varieties of the ore, of greater or lesser
purity. Above coal bed No. 55 there is a seam of iron, with oyster shells, apparently Ostrea subtrigonalis, or the same species
found so abundantly near Brown and O’Bryan’s coal mine, about twenty miles southeast of Cheyenne. Nearly a dozen openings
have been made here for the coal.
A beautiful valley has been scooped out by the South Boulder, leaving a bench covered with debris between the two Boulder
creeks. Before reaching these huge sandstone walls, we pass over a portion of the cretaceous, and a great thickness of the red beds,
inclining at a high angle.
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Immediately south of the South Boulder creek there is a high bench that extends up close to the base of the mountains, and is
covered with drift and boulders, three miles in width, concealing all the unchanged rocks. However, in the valley of Coal Creek
seven beds of coal are revealed by the scooping out of this valley. These beds all incline at a high angle, about 45°, and are not
easily worked. The sandstones project up above the loose material like irregular walls, and the creek itself forms a narrow passage
or gorge through one of these ridges.
Between the sandstones, and apparently with very little clay either above or below, is one bed of coal four to six feet thick,
which was wrought for a time, and then abandoned.
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HISTORY OF FRONT RANGE COAL
When heavy settlement began during 1858 and 1859, the immigrants from coal bearing eastern states quickly recognized the
wealth of these thin coal seams. Certainly not the quality or quantity of the eastern beds, these coal beds still could supply enough heat to
warm a house in a landscape barren of trees.
William and Nancy Kitchens opened the first coalmine in Marshall, called the “Washington Lode.” Eventually by being exposed
to the air and a spark or two, it spontaneously combusted. The fire is still burning, not so deep underground that it might not cause
problems for potential builders on both sides of Route 93. (Sampson, 1995, p. 6)
Within a few short years settlers opened many “wagon” mines from Marshall all the way south to Littleton. Burt and Berthoud
showed three mines as early as 1862. (Map 3) Berthoud described the first fossil leaf he found:
In the carboniferous sandstone a few miles north of Golden City, we have discovered a fossil plant, apparently a
dicotyledon, which would indicate a tertiary formation; but the fossil was too indistinct to decide the question by a single specimen”
(Burt and Berthoud, 1862, p. 35)
Coal is also found in the valley, beneath a white granular sandstone and in veins, interstratified with shale, of from one to
thirty inches thick. It is apparently of the tertiary formations, though no distinct fossils have been found to decide the matter
paleontologically, yet the general character of the coal itself, the contiguous rocks and plausible theory of a geological modern
formation of the whole country, would provoke the decision that this is one of the most recent carbonaceous deposits on the
continent. The coal obtained at depths below atmospheric influences, is compact, breaks with a slight-conchoidal fracture, glossy
and clean. We have had no opportunity as yet to test specific gravity or analyze the coal. It is mined, and used extensively by
blacksmiths throughout the country and appears to contain more bituminous and volatile matter than any fuel we ever saw; as the
smith say, it is very resinous. It would be a valuable article for the manufacture of coal oil. There appears to be an abundance of it,
and several pits have been opened in the outcrops. (Burt and Berthoud, 1862, p. 35)
Joseph M. Marshall (Photo 2), one of the founders of Colorado’s iron industry, realized the importance of controlling the
coalmines to the future of the mining and iron industries, and the railroads. He purchased the little wagon mine from Kitchens in 1866
and, through a government Land Grant, enlarged the operation into a business that lasted for almost 80 years around Marshall(Sampson,
1995, p. 6). He and his cronies controlled the “company towns” and the miners’ lives to a degree unknown in today’s free America.
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MAP 2. BURT and BERTHOUD’S (1862) MAP SHOWING FRONT RANGE COAL MINES
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THE ORIGINAL MINES
Jone Heivner first found the coal deposit at the base of Ralston Creek. In 1865, he sold the claim to Murphy, Loveland, and Armor
(Ramstetter’s, 1999, p. 46). By 1869, D.M. Murphey owned the Ralston Creek Coal Bank outright. He had enlarged the original mine
shown by Burt and Berthoud in 1862. It boasted an accurate Fairbanks scales. (Figure 2) At his mine between Rocky Flats and Golden,
one mile north of Ralston, Martin Lyden also had a Fairbanks Scales by March 16, 1870. (Figure 3) Five miners died in a major mine gas
accident in the 1860s. In 1911, the mine was destroyed in a terrible fire that killed ten miners. Mattie D. Merrick, whose husband, Frank,
died in the fire, brought suit against the Leyden Coal Company but lost. Later that year the company announced plans for a concrete shaft
(Ramstetter’s, 1999, p. 67).
FIGURE 2. Murphey’s mine Ad 1869
(Ramstetter’s, 1999, p. 46)
Lyden’s
(Ramstetter’s, 1999, p. 67)
FIGURE
3.
mine Ad 1872.
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LOADS OF COAL
Hayden reported on the Murphy mine.
The next finest exhibition of coal in Colorado, to Marshall’s mine, is that of the Murphy mine, on Ralston creek, five miles
north of Golden city. The coal bed is nearly vertical in position, and varies in thickness from fourteen to eighteen feet, averaging
sixteen feet from side to side. There are nine feet of remarkably good fire-clay on each side of the coal, and above and below, or on
the west and east sides, are the usual beds of sandstone. This mine is very near the foot of the mountains, and the belt of
sedimentary rocks, which are all nearly vertical, is very narrow here-not more than half a mile in width-and are mostly concealed by
debris.
Mr. Murphy thinks that there are eleven beds of coal within the distance of one-fourth of a mile, all nearly or quite vertical
in position, or which the one opened is probably the oldest. The mine is opened on the north side of the creek, and may doubtless be
followed above waterline several miles to the northward, toward Coal creek.
On the south side of Ralston creek the same bed has been opened, and the indications are that it may be followed the same
way southward, toward Golden City. The entire surface is so covered with superficial deposits, and grassed over, that it is
impossible to work out these beds in detail, and the artificial excavations afford us the most reliable knowledge. A hundred yards or
more west of the coal there is a high ridge running parallel with the mountain range, capped with lower cretaceous sandstones, No.
1. (p. ?)
In 1872, Robert Old touted the immense coal reserves evident along the Front Range and throughout Colorado.
Coal. Brown or ligneous, existing in veins (vertical and more or less horizontal) 3 to 12 and 13 feet thick, being mined
extensively at Golden, north along the base of the mountains to Boulder, and at Erie; has been supposed will be discovered
bituminous, although not yet known to exist; is found in southern Colorado, near Canon City, very hard, clear, and free from
sulphur; also in the South Park, with the smooth, shiny, clean appearance of cannel [a type of bituminous coal]; one vein, within a
mile of the McGlaughlin Ranch, showing 6 feet thick; and in the Middle Park as an albertine, reported upon by Professor Denton, as
outcroping [sic] over an extensive area, and laying in veins 3 feet wide”. (Old, 1972, p. 16)
The railroad was on its way to and through Colorado. Steam engines powered mining equipment. Coal burning smelters were
erected in many mountain towns, Golden, and Denver. Housing demanded coal for heating. Eventually coal burning power plants
provided electricity for the mines. Coal was vital to the entire economy and the future of Colorado.
MAP 3. MINED OUT AREAS OF LAFAYETTE, LOUISVILLE, AND MARSHALL AREA (Colton and Lowrie, 1973)
15
RED ASHES and BLACK DUST
On the ridge north of the road, along Davidson Mesa, sat the Old Crown mine adit. Then came the Ross, the Pittsburg, and the
Red Ash. Observe the red clinkers that came out of the burning coal layers that gave Red Ash its name.
The Marshall coal district produced from the Laramie Formation consisting of sandstones, shales, and coal beds that total about
750 feet in thickness. Many beds of coal are interlayered with the sandstone and shale, but only a few are thick enough to mine. The
coal formed from vegetation, buried, and preserved in thick layers in ancient tropical swamps. As the vegetation was compressed, it
was changed to coal by the heat and pressure caused by burial under the overlying sediments. Many beautiful specimens of fossil plant
leaves have been found in the sandstone that forms the surface of the hill at the old mine in Marshall. The sandstone is repeated several
times by steep faults trending northeast. The coal was principally lignite, satisfactory for generating steam and smelting ores. It was
also free from oily and sooty substances and had only the slightest trace of sulphur-qualities. This made it desirable for domestic use.
From 1859 to 1956, three years short of a century, coal mining dominated this area until the latest owner, Rocky Mountain Fuel
Company, filed for bankruptcy.
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PHOTO 1. Abandoned miners’ houses at Superior (Hornbein, 1976, p. 249) The Boulder County Maria Rogers’ Oral History Program
at the Carnegie Library is compiling a complete history of the town of Superior, interviewing all residents who lived in the company town.
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THE RUNNING OF THE RAILROADS
This is the Colorado & Southern grade, constructed in 1908 as part of the Denver & Interurban’s “Kite Route.” [What is?]
In 1872, Marshall, Langford, John W. Nesmith, the manager of the Black Hawk foundry, and two other men organized the
Marshall Coal and Transportation Company. The company dealt in coal and built wagon roads and shops to move the coal to its
market. The amount of coal extracted from the mine at Marshall during the middle 1870s was limited by this simple transportation
(Greiner, 1967, p. 312).
In 1876, Moffat and his partner, Jerome Chaffee, had purchased the Caribou silver mine, fourteen miles west of Boulder.
Moffat knew that both gold and ore needed to be transported. He had previously built the Boulder Valley branch on the Denver Pacific
west from Hughes to the coal banks at Erie. This railroad supplied the Denver Pacific locomotives with the coal they needed for fuel,
and Erie coal also was used in the towns along the lines of the two railroads. (Greiner, 1967, p. 309)
Some of the movers and shakers of the Golden, Boulder, and Caribou were the principals in the First National Bank of Denver.
Theodore Lyster was the bank’s assistant cashier; he was a brother-in-law of Walter S. Cheesman. Thomas Moffat, the secretary and
treasurer, was David Moffat’s older brother. Junius Berkley was an attorney and member of the board of regents of the new University
of Colorado. Lemuel McIntosh was a rancher and the fifth director. John Bush of Golden, supervised the construction.
The Golden, Boulder, and Caribou incorporated Oct. 26, 1877, and a few weeks later the Marshall Coal Mining Company was
chartered. Its movers and shakers were Nathaniel P. Langford, Augustine’s older brother, future governor of Montana and first
Superintendent of Yellowstone, president; Augustine Langford, secretary; and Samuel S. Davidson. A. Langford had sold his interest
in the foundry at Black Hawk and had returned to Denver to organize the Colorado Iron Works with Davidson and others in 1875.
John Titcomb was the surveyor of the Boulder-Marshall line. By Nov. 14, 1877, all the contracts for grading, bridging, tieing,
and ironing were signed, and the directors anticipated that their crew of 75 men would complete the railroad within three months. The
real town of Marshall grew during this three months. Seventy-five miners opened new chambers in the mine, stockpiling coal in
preparation for the railroad. A trestle and shute were under construction from the mine to the railroad line. Several houses and the
inevitable saloon were built. There was a railroad depot and section house in Marshall. (Sampson, 1995, p. 8; Greiner, 1967, p. 314)
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PHOTO 2. Joseph M. Marshall (Greiner, 1967, p. 311) PHOTO 3. Augustine Langford (Greiner, 1967, p. 313)
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THE POSH PARTY
On February 21, 1878, a Sunday afternoon, a number of well-dressed ladies and gentlemen stepped from a train at
Marshall, Colorado, and upon being furnished with lighted miners’ lamps, began a tour of the Marshall coal mine. Great
admiration and surprise were expressed at the fine condition of the mine and the eleven-foot thickness of the coal vein. After a
thorough exploration, the party returned to the train for an excellent dinner prepared by Cella, Denver’s famous restaurateur.
The hosts for the afternoon’s festivities were David H. Moffat, Thomas W. Moffat, and Theodore G. Lyster; and their guests.
[They] filled two passenger cars, [and] had come from Denver, Golden, and Boulder to celebrate the completion of the Golden,
Boulder, and Caribou Railroad between Boulder and the Marshall coal fields. (Greiner, 1967, p. 305)
The first carloads of coal came into Boulder over the Golden, Boulder, and Caribou branch on March 5, 1878. The freight cars
furnished by the Denver, South Park and Pacific and Colorado Central had a capacity of ten tons.
The railroad owners then took a ten-year lease on 1,480 acres from Marshall on February 12, 1878, and operated the coalmines.
During the first year of operation, 25,000 tons of coal traveled over the six miles of tracks into Boulder, slowly. The run into Boulder
took 20 minutes. The following year, 1879, tonnage increased to 50,000, or almost 1/5 of all the coal produced by the mines of
northern Colorado. An average of fifteen to twenty carloads a day passed over the line in 1879 (Greiner, 1967, p. 319). In 1885, an
estimate determined that the train traveled over six thousand miles between the two towns (Greiner, 1967, p. 322). Few passengers
rode the train. The fare was 21 cents, and in 1885, only 271 persons took advantage of the ‘light’ rail.
In November of 1879, Lyster announced that the Golden, Boulder and Caribou would build an extension to the Fox coal mine, a
mile northeast of the Marshall mine. Michael Fox had opened the bank the year before; its output sometimes reached fifty tons a day.
The nearby Black Diamond mine, operated on a small, sporadic basis, also added its coal to the tonnage carried by the railroad
(Greiner, 1967, p. 320). By 1882, the value of coal was $2.50 per ton. The charge for freighting ranged from 7.7 to 8.6 cents per ton
per mile . The railroad’s total income from freight, averaged $28,641.12 a year for 1883, 1884, and 1885 (Greiner, 1967, p. 322).
Other fright included stone, steel, castings, lumber, agricultural products, and goods and products bound for the mines and the small
community of Marshall.
In November of 1879, Jay Gould purchased the railroad from Moffat. In January of 1880, the Kansas Pacific, merged with the
Denver Pacific, the Union Pacific, and the Colorado Central to form the Union Pacific Railway Company.
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PHOTO 4. Marshall Mesa. Taken 1970. (Biggins and Dodson, 1970, p. 5)
21
LANGFORD (photo 5)
At that time, 1882, the town of Marshall’s name was changed to Langford (Greiner, 1967, p. 321). From 1881 through 1885,
excluding 1883, an average of 47,038 tons a year was taken from the slopes at Marshall (Greiner, 1967, p. 321). The Fox mine
produced an average of 23,490 tons annually.
In 1885, the Union Pacific purchased the property and rights belonging to the Denver, Western and Pacific. They completed a
new railroad from Denver to Boulder by way of Marshall. The railroad reached the mines by August of 1886. This railroad brought
trains directly through the University of Colorado campus, then down the hill to the depot on Water Street (now Canyon Street). In
Boulder, the Andrews Arboretum on Broadway south of Arapahoe is part of the old right-of-way that ran through campus. (Sampson,
1995, p. 8)
Augustine Langford died in 1885. At the end of that year the Marshall Consolidated Coal Mining Company was organized to
work the mines. Incorporators included Jerome Chaffee, Walter Chessman, and George Kassler. Kassler had become cashier of the
First National Bank of Denver in 1880 after David Moffat was named president. (Greiner, 19767, p. 323)
In 1890, the Union Pacific, Denver & Gulf consolidated a number of railroads, including the Denver, Marshall, and Boulder. It
operated the railroad through Marshall until 1901 when the Colorado & Southern (C&S) took over. One of the first C&S priorities was
to add a spur from the main track east of Marshall, west and north to the Fox Patterson mine. (Sampson, 1995, p. 8)
In 1908, the C&S Denver & Interurban Railroad Company (D&I) initiated a transit service called “The Kite Route”. The train
ran 18 round trips between Denver and Boulder every day. It made a closed circle around the kite-shaped route going in one direction
via Marshall and in the other via Louisville, meeting east of these towns at the Louisville Junction. From there the train chugged into
Denver on the “string of the kite.” (Sampson, 1995, p. 8)
This railroad shut down in 1932 when the Marshall branch was abandoned and the track pulled from the Water Street depot to
the Crown Mine spur several miles east of Marshall. (Sampson, 1995, p. 8)
22
PHOTO 5. Langford (Biggins and Dodson, 1970, p. 27)
23
PHOTO 6. Boarding house at the Marshall mine (Greiner, 1967, p. 314)
PHOTO 7. The Gorham Boarding House (Sampson, 1995, p. 20).
Photo 6
Photo 7
24
A CRACKERJACK of a mine
Continue up path.
Cross Community Ditch.
Can you imagine doing your laundry in the ditch?
Turn east on trail along ditch to the remains of the Crackerjack Mine.
Investigate remains of mine tipple, adits, and shafts.
Walk on up the hill to get an overview of the valley.
Compare to Arthur Lake’s sketch from 1898.
Compare to photos in “Walking Through History on Marshal Mesa”
Ponder what life must have been like in this valley in the late 1800s.
In 1885 the Marshall Consolidated Coal Company owned $2 million in capital stocks, but the miners lived close to the
poverty level. Company stores charged exorbitant prices and wages were extremely low. Miners had to buy their own black
powder, lights, and tools. They had to pay monthly fees to the company doctor and to the company blacksmith. They paid rent
for the company houses in which they lived and they paid for the coal they used in their homes. Miners often were paid less
than 50 cents per ton of coal they mined. Sometimes when a miner went to draw his wages he found he had nothing left after
the money he owed the company was docked. That was called a “bobtail” check. (Sampson, 1995, p. 7)
Miners’ houses ranged from shacks to dugouts, company houses, and sturdy rock homes. Company stores, boarding houses
(Photo 6/7), blacksmith shops, and mine structures filled the valley. There was a meat market, a post office, and many saloons and
pool halls. There were bathhouses for the miners and a school for the children. Tipples stood at the mouth of every mine opening.
(Sampson, 1995, p. 8)
What was life like just beyond at Eldorado Springs in 1916 when Dwight and Mamie Eisenhower honeymooned at the resort?
Look across the valley to the north. On the north side of the road, there are a series of rectangular holes, each about the size of
a large room in a house. These collapse features are mine subsidence into the old tunnels.
Return to parking lot.
Drive west to back to Marshall.
25
MAP 3. Map showing the Marshall road
Route 93 before straightening at the
modern intersection (Malde, 1955, Plate 7)
and
26
MARSHALL
The small long building behind the wall constructed of Lyons sandstone north side of road was the company store for the
Marshall Mine. It is pictured in its original state in Joanna Sampson’s Walk through History on Marshall Mesa.
Cherryvale Road comes in from north.
The old school house, refurbished by the owners stands to the north.
Old Marshall Road to the right fork.
Go along old railroad grade cut through Laramie Formation on Marshall Road.
Some scientists believe that this cut through the coal vein caused the atmospheric oxygen and sparks from the locomotive to
combust the coal in Marshall Mine #1. The coal fires have been burning for 130 years. No one knows the actual depths and extent of
their penetration.
In the 1860’s, Marshall, also known as Langford and Gorham, was one of the toughest, brawlingst coal camps in the west. In
the early days, Marshall’s population was greater than that of Boulder, an agricultural town.
Augustine G. Langford (Photo 3) owned the first iron foundry in Denver, located in Auraria on Blake Street, between Second
and Third,near where the stadium is today. At that time material for making castings was scarce and the limited supply came from
broken or misfit parts of heavy stamp mill machinery, old stoves, and other small parts of cast iron. (Greiner, 1967, p. 312; Sanford,
1931, p. 142)
Joseph M. Marshall was a partner in the Langford foundry. He is [incorrectly] given credit for the original discovery of the
exposures of coal deposits on South Boulder Creek in 1859 (Sanford, 1931, p. 143). Marshall had also noted, in the same vicinity,
concretions or nodules of hematite (an oxide of iron) that occurred in the sandstone and shales and underlying the lime sheet. Because
of the shortage of scrap iron, Marshall suggested using the native iron ore.
A furnace was erected near the foundry, and ore, lime rock, and coal were hauled from here to Denver (Sanford, 1931, p. 144).
The Rocky Mountain News reported on May 27, 1861:
Langford & Co., proprietors of the Denver Foundry, brought a ‘pig’ of “pikes Peak iron’ to our office, a sample of
some fourteen hundred pounds produced in their blast furnace a few days ago in a six hours’ run. It was from native ore,
yielding thirty-five to forty per cent of metallic iron of a very fine quality.”
27
Now that it is demonstrated that iron sufficient to supply the wants of the country can be manufactured here cheaper
than it can be imported form the states, we hope companies will be formed with sufficient capital to open and work our mines
extensively. (Sanford, 1931, p. 144)
28
MR. MARSHALL AND HIS FURNACE
Langford & Co. was the first to enter the arms production industry in Colorado. John W. Nesmith bored out and finished
a two-inch bore cannon fired for a celebration in Denver on July 4, 1861. (Sanford, 1931, p. 144; Sampson, 1995, p. 7)
In 1862, after opening the First National Bank of Denver, Marshall sold his share of the foundry to Langford and William and
Milo Lee, who soon transferred operations to Black Hawk. (Greiner, 1967, p. 312)
In 1864, Joseph Marshall left Langford & Co. He erected a blast furnace on South Boulder Creek (at Marshall). The first blast
occurred in June of 1864. The furnace constructed of laid up stone stood along the north side of the ditch, within a few steps from a
point where the Eldorado Springs road branches from the Denver-Boulder highway via Marshall. (MAP 5)
Back of the wall and some twenty feet higher, runs the Goodhue irrigating canal with seepage through the crevices that gathers
a little below and forms a rivulet (Sanford, 1931, p. 145). Marshall built the ditch to this point, where sufficient volume operated an
old-fashioned “overshot” waterwheel that furnished power for the blower and for other requirements. Later the ditch was enlarged and
extended eastward for irrigation. (Sanford, 1931, p. 145)
Marshall had problems with his operation. Working out the exact proportions of ore and fluxing materials, keeping the stack
from ”freezing”, in addition to defending their families and homes against invasions of hostile Indians who came from the plains.
(Sanford, 1931, p. 146). During his iron industry development, Marshall discovered that 4,400 pounds of ore mixed with limestone
and charcoal produced one ton of excellent quality gray pig iron. The iron plant operated on charcoal supplied by the McGinn family,
who lived at the mouth of Eldorado Canyon, two miles west. However, his heaths were a disaster and burned out twice in a short
period of time. (Sampson, 1995, p. 6)
In 1866, Bayaud Taylor, travel writer for the New York Herald Tribune, stopped here on his way to a speaking engagement in
the now ghost town of Valmont (the Valmont Power Plant occupies the area now). In his words:
This is a charming little valley, at the base of the mountains. The outcropping of limestone and the black piles at the
mouths of coal drifts indicated our approach to it. On dropping into a little winding hollow, we soon saw the massive smelting
furnace surrounded by clustered cabins. Mr. Marshall, the proprietor, received us at the door of his residence, and, after dinner,
piloted us to the furnaces and mines. There are eleven veins of coal, varying from four to twelve feet in thickness, in the space
of half a mile; iron ore of a richness of fifty per cent just beyond it, and the best limestone, in almost inexhaustible quantities.
Mr. Marshall, however, has only experimented with the native ores sufficiently to establish their value. He finds it more
profitable to buy up abandoned machinery at a trifling cost and recast it. The furnace is not only substantially but handsomely
built, and has thus far done a thriving and successful business for its owner.
29
The Marshall furnace produced successfully for at least two years and then ceased soon after Taylor’s visit.
30
PHOTO 8. The remains of the first furnace, taken May 1931 (Sanford, 1931)
31
THE NEW INTERSECTION
Turn left at stop sign.
The original route 93 sat further west, just past the houses on the southwest corner (Map 5). The intersection and the new
Marshall Bypass were put through as a response to handling increased traffic to new arms establishment at Rocky Flats in the 1960s.
Turn Left (south) onto Route 93. Proceed up hill.
The yellow sandstone is the Fox Hills Sandstone. The Fox Hills is a deposit of beach sand, laid down along the edge of the
Cretaceous Sea as the sea retreated from this region for the last time. The Fox Hills is a useful aquifer for ground water in the county.
It has been cut and repeated by faulting (along route 93 - amazing the fault was kind enough to follow the road!). You will cross the
Fox Hills several times as you continue up in elevation for about a mile.
1.8 Move to left turn lane coming down the hill. Intersection of CO 128 with CO 93.
Turn left on 128. Greenbelt Plateau Trailhead on left
This highway now connects Wadsworth (Route 121) with Route 93, and is another “new road” that bounds Rocky Flats on the
north.
0.2
Cross Coal Creek
At several locations southward from Marshall the roads cut into the soft, yellowish-brown clays of the Cretaceous Pierre Shale.
West of Highway 93 at the Jefferson County line there is a large quarry in the clay beds. The shale from this pit is roasted and
converted into lightweight aggregate for use in making concrete. The Pierre Shale is the stratigraphic type sections for the evolutionary
zones of the ancient squid Baculites.
The Gorham and the Pluto Mines were north of here along the valley walls carved by Coal Creek.
0.3
Windmill farm on right.
1.7 Prepare for stop. Cross road and park on wide NORTH shoulder.
32
THE ORIGINAL IRON
STOP 4. COLLECTING IRON. (COPROLITES)
Looking westward, Long's Peak is the big mountain to the northwest. The Flat Irons behind Boulder are straight ahead.
Eldorado Mountain, the site of a radio antenna controversy, is the mountain slightly to the southwest.
Cretaceous Pierre Shale outcrops in the roadcuts on both sides of the highway here, overlain by the Rocky Flats Alluvium. On
the south slope is a major slump block which illustrates the landslide problem along the alluvium/shale contact. At the west end of the
outcrop is a second slump block. The “toe” being removed during roadbuilding caused both slides.
At this outcrop look for large ironstone concretions and conspicuous iron layers about one foot thick. Sometimes these
concretions will be as big as 18" across, with an ammonite or other fossil in the center. There are plant fossils in the iron layers. Also,
look for small, round disc-shapes resembling fossil cow patties. These are cone-in-cone structures, a concretion formed by bacterial
decay in shale layers. The cone-in-cone structures here are relatively small, but numerous. Some contain nicely developed crystals of
calcite.
On the north side of the road, look for extremely black shale in the eroded ditch. The coal layer just above this black shale l is
in the basal Laramie Formation.
COLLECTING: It is okay to collect cone-in-cones, ironized fossilized wood, coal-like shale, shale, ironized coprolites, and
metamorphic rocks and igneous rocks from alluvium. You will also collect muddy shoes.
Return to cars. Continue east. Pull out with care.
0.6
McCaslin Blvd. on left.
The Rocky Flats Alluvium may be 1-10 m thick and locally as thick as 30 m or more. It rests on an irregular bedrock surface.
Quartzite (70-80%) and granodiorite, and gneiss (10-20%) are the dominate the clasts. The quartzite crops out for several kilometers in
the lower part of Coal Creek Canyon, but granodiorite and high-grade metamorphic rocks underlie the bulk of the drainage.
Apparently, the quartzite outcrops were the main contributors to the alluvium, probably deposited during a Plaistocene glacial age
Pleistocene.
33
LANDSLIDES
0.3 Intersection of 128 (120th) and Indiana. Turn right (south) onto Indiana.
Irrigation and liquid waste disposal in the type of situation where there is a gravel-covered upland surface underlain by clays
intensifies the potential landslide problems on the steep, bounding escarpment slopes. The gravels generally meet percolation
standards for soil-absorption septic tank systems. However, the water from irrigation and septic systems moves along the base of the
gravels, exits as seeps along the hillsides, or saturates the overburden, and slides ensue.
Landslides are numerous along the margins of the Rocky Flats surface. From here, landslides are prominent along the slopes of
Rock Creek valley. Flows, slumps, slides, and complex landslides are recognized. Landslide ages range from middle Pleistocene to the
present. Most are very young. They have crescent-shaped head scarps and lobate toes. Landsliding probably began soon after the
streams cut through the Rocky Flats Alluvium and exposed the underlying Upper Cretaceous bedrock. Local saturation by the perched
water table at the Rocky Flats alluvium/bedrock contact, unstable slopes underlain by bedrock prone to failure because of numerous
bedding planes that can serve as slip surfaces, and abundant claystone with expansive clays all contribute to extensive landsliding.
0.4
Walnut Creek. Northwest drainage of Rocky Flats
0.4 Cut exposes Arapaho Formation under Verdos Alluvium
0.2
0.3
Great Western Reservoir to the east. Great Western’s dam broke while under construction in response to movement during the
1968 earthquakes. Movement of rocks as a result of “lubrication” by injection of fluids into deep wells at the Rocky Mountain
Arsenal caused the earthquakes.
Rocky Flats east entrance. Verdos Alluvium with calcic soil on top of Arapaho Formation in cuts around entrance.
0.3
Slocum (high terrace) Alluvium
0.7
Protection project for Standley Lake (no entrance)
0.4 Intersection with 96th Avenue
1.3
To the east is Standley Reservoir.
To west is the new reservoir for the city of Arvada. Wanna drink that water?
34
0.2
Intersection of C 72 with Indiana. Continue south on Indiana
Route 72 is on Verdos Alluvium.
The Verdos Alluvium was originally named from a deposit in Ralston Creek. Within the
Verdos is a volcanic ash considered equivalent to the Pearlette Ash Member of the Sappa Formation in Nebraska. Other ashes
associated with the Verdos Alluvium are considered equivalent to the Lava Creek ash derived from the Yellowstone Caldera. Hence,
the Verdos Alluvium is approximately 640,000 years old. [Reference?]
35
LEYDEN
0.3
Turn right on Leyden Road.
0.3
Denver Formation in cut on north side of road.
1.4
Leyden Lake on the south side of road.
0.4 Public Service Facility on north side of road
0.4
Town of Leyden
0.2 Look to the northwest, up Barbara Gulch for a good view of drainage off Rocky Flats.
1.9
On the north is a sanitary landfill operated by BFI, filling in the old clay pits with environmentally tested and sound trash.
Notice the gas line equipment. On the north side of the road is a gaging station that sits on the tailings from an old coal mine.
Watch for other tailings and remnants of mining operations along this road. Think about the potential of this gas storage operation.
Natural gas pressurized in an old, leaky much-faulted mine just downstream from Rocky Flats that is down flow from underground
mine fires in Marshall. [Huh ?????] Put a number of reservoirs on top of Rocky Flats and Marshall Mesa. Watch what happens when
someone lights a match in Lyden Gulch.
Continuing west on Leyden Road, look at the meanders in Leyden Creek as it excavates into the Piney Creek Alluvium. Notice
the undercut banks and slump blocks along the south slope of the creek.
0.3
Leyden Ridge. We will NOT stop here today.
Leyden Ridge, coal, and clay mining. (Photo 7)
LEYDEN COAL MINE
The view to the north is the vertical wall of Leyden Ridge, a famous site that has been stripped of clay on the west side and
emptied of coal under and to the east. Now it is being filled with garbage on the northeast. For many years Public Service stored
natural gas underground in the mine workings.
36
The vertical beds of yellow sandstone north of the road are the Fox Hills sandstone. The Leyden Coal Mine, like the Marshall
mines, was developed in the Laramie Formation, exposed just to the east beyond the Fox Hills. The coal was mined from two very
gently dipping beds about 100 feet apart vertically and about 600 and 700 feet below ground, respectively. The pits at the bottom of
the vertical bed of the Fox Hills are abandoned kaolinite clay pits. The clay was removed for brick making by the Lakewood Brick
factory before 1950. The latest mining efforts in the Laramie here at Leyden extracted low-grade uranium ore from the Fox Hills
Sandstone.
37
BERTHOUD Described the LYDEN - 1875
In 1875, E.L. Berthoud, a famous Colorado surveyor and engineer, reported “On the occurrence of Uranium, Silver, Iron, etc. in the
Tertiary Formation of Colorado Territory” at the Academy of Natural Sciences in Philadelphia. We will stop by Lyden’s Ridge on the field
trip.
On November 24th, 1874, I was called upon to measure and examine a coal mine called the Lyden Coal Mine, six miles
north of Golden, Colorado Territory. The Lyden coal mine of Jefferson Co., Colorado Terr., lies in Section Twenty-eight (28),
Township 2 S., Range 70 west, C.T. about 1 ½miles east of the metamorphic and eruptive rocks of the five ranges of the Rocky
Mountains. The trend of the outcrop of cretaceous and tertiary strata that here are locally known as “Hogbacks’ is N.17 degrees to
N.19 degrees west, which is also that of the coal beds intercalated in the tertiary shales, clays and sandstones. The coal and its
accompanying walls are nearly vertical but they occasionally dip 5 degrees, 7 degrees, 8 degrees to the west, causing a local
inversion. (Berthoud, 1875, p. 363)
Berthoud painstakingly described Lyden’s Ridge and the coalmine.
The Lyden coal mine lies in an oblong ridge, isolated mostly in a small basin of erosion one mile north of Ralston Creek.
The ridge, with its weather-worn castellated summit, is 700 or 800 feet wide, and nearly one-half mile long; a parallel outcrop of
cretaceous sandstone, dipping east about 30 degrees, and succeeded by a ridge of red sandstone, is found one mile west of the coal
outcrop. In order then to reach the coal bed in the cheapest and most expeditious manner, a drift was started form the west slope,
and, cutting at right angles to the stratification, reached a distance eastwards of 310 feet horizontal, and over 200 feet below the top
edge of the sandstone outcrop. At about 270 feet from the entrance of the drift, a small vein of coal was pierced through, about 15”,
then two more larger beds, making altogether about five feet of good coal in three beds. (Berthoud, 1875, p. 364)
Photo 9. Leyden Ridge (Mitchell, 1997, p. 52)
Original Lyden
Mine adit
Uranium mine with clay pit to
the north
CHOKE DAMP
38
Interestingly, Berthoud (1875) was called to the mine to examine an:
exceedingly hard black vein of mineral matter, containing geodes of brilliant quartz crystals, and small veins of pyrite, the
honeycombed mineral full of a green ochre powder, with veins of chalcedony, and small orange-colored crystals and
concretions.(Berthoug, 1895, p. ?]
He (Berthoud, 1875) described the vein of mineral matter in detail along with the various drifts in the Lyden Mine. By that time,
one drift was nearly 200 feet or more in a northerly direction on the workable coal bed. The strange black layer occurred below that drift on
a drift that Berthoud had entered from the south end of the “hogback”. Sixty feet into the drift, the “dike” or bed of metamorphic iron ore
cut the coal bed completely off. The miners had followed the face of the bed of ore, and 15 feet up where it turned back into coal again.
Berthoud gives one of the first records of death in the coalmines:
The mine was worked for a long distance northwards, until a sudden flow of choke-damp killed all the miners...The drift
was abandoned, and the new drift driven crosswise to locate and open up the workable coal bed. (Berthoud, 1875, p. 364)
Choke-damp was the miners’ term for carbon dioxide gas (Meyerriecks, 2002, p. 47). The spelling Lyden is the original; the
modern term Leyden was probably adopted by the railroad sometime during its history.
Berthoud compared the coal from the Lyden with the coal from the Murphy (original spelling- Murphey), Coal Creek, and Golden
coal. By 1875, Arthur Lakes and the Hayden Survey had collected the fossil plants of the Tertiary beds and Lesquereux had
identified“Cinnomomum platanus, Pharagmites, Magnolia platanus, and Juglens (Berthoud, 1875, p. 364).
END OF TRIP
Proceed west on Leyden Road to intersection with Route 93. .
If you need to return north, turn right.
To return south turn left on 93. Proceed to the Loaf ‘n Jug at Iowa Drive in north Golden for a cup of coffee. If time allows,
visit the Coal Miners Monument on the CSM Campus at 12th and Elm St., near the football field.
Hope you learned a lot about the local area, geological hazards, and the life of the coal miners in Colorado.
39
Photo 10. The White Ash and Loveland Coal Mines in Golden (DPL Western History Collection)
40
FOR FURTHER REFERENCE
Berthoud, E.L., 1875, On the Occurrence of Uranium, Silver, Iron, Etc., in the Tertiary Formation of the Colorado Territory, Proc.
Acad. Nat. Sci. Phil., p. 363-356.
Biggins, James and Dodson, Max H., eds., 1970, Marshall Mesa Natural Area Study, unpublished paper, Departemtn of Geography,
Boulder, U. Colorado
Burt, S. W., and Berthoud, E.L., 1861/2, The Rocky Mountain Gold Regions, Denver City, J. T., Rocky Moutanin News Printing Co.
Brown, Robert, 1985, The Great Pikes Peak Gold Rush: Caxton Printers, Ltd., Caldwell, Idaho, 124 p.
Colorado Geological Survey, Special Publication #1, Governor's Conference on Environmental Geology: Denver, Colorado, April 30May 1,2, 1969, An Environmental Geology Field Trip Road Log. p. 68-78.
Colton, Roger B. and Lowrie, Raymond L., 1973, Map Showing Mined Areas of the Boulder-Weld Coal Field, Colorado, USGS, Misc.
Field Studies Map MF-513
Eckel, Edwin, et. al., 1997, Minerals of Colorado: Fulcrum Publishing, Golden, Co.
Greiner, Jean M., 1967, The Golden, Boulder, and Caribou, Colo. Magazine, V. 44, #4, p. 305-323
Malde, Harold E., 1955, Surficial Geology of the Louisville Quadrangle: USGS Bull 996-E
Mitchell, James, 1997, Gem Trails of Colorado, p. 55
Petrie, Brent, 1976, Map showing outstanding Natural and Historic landmarks of the Greater Denver Area, Front Range Urban
Corridor, Colorado: USGS Misc. Inv. Ser. Map I-856-F.
Runnels, Donald D., 1980, Boulder, A Sight to Behold Guidebook: Johnson Publishing Company, Boulder, CO.
Sampson, Joanna, 1997, A Walk through History on Marshall Mesa: Boulder County Open Space Pamphlet.
Sampson, Joanna, 1997, Personal Communication throughout 1997.
Sampson, Joanna, 1998, A History of Eldorado Springs State Park.
Sampson, Joanna, 1997, Remember Ludlow! Co. State Historical Society
Sanford, Albert B., 1931, The First Iron Manufactory in Colorado, Colo. Mag., V. 8, #4, p. 142-1446.
Taylor, Bayard, 1866, Colorado: A Summer's Trip: U. Colo. Press, p. 157
41
Van Horn, Richard, 1972, Surficial and Bedrock Geologic Map of the Golden Quadrangle, Jefferson, Co: USGS Map I-761-A
Weimer, Robert, and Sonnenberg, Stephen, 1996, Guide to the Petroleum Geology and Laramide Orogeny, Denver Basin and Front
Range, Colorado: Colorado Geological Survey Bull. 51.
Wells, John D., 1967, Geology of the Eldorado Springs Quadrangle Boulder and Jefferson Counties, Colorado: USGS Bull. 1221-D
42