As the IceAge ended about 15,000 years ago, Tualatin
was carved by a series of gigantic floods bursting down
from broken ice dams in today’s
northern Idaho,Montana and
Canada. The waters moved
icebergs carrying unusual boulders
as large as cars. Called “glacial
erratics”,these monoliths were
strangers to our region and are still
being discovered today. Scientists
believe over 300 feet of water
rose above where our residents
and visitors now work, shop, live
and play. After roaring in like a
tsunami, the massive waters would
then rush back, creating channels
that we drive through on I-205 and
pass over at I-5 Nyberg Exit 289.
In recent times the bones of
mastodons, sloths and other megafauna have been discovered and
are on display at Tualatin Library
and Heritage Center. As the Ice
Age ended, these giant animals
likely found the Tualatin area to
be just as hospitable as we know it
today, with plenty of forage in the
vicinity. Tualatin’s first peoples
also found this region to be an
ideal living environment with all the resources needed to
thrive until strangers and diseases would come many years
later.
Tualatin resident Bill Baker,
internationally-known consultant
on tourism, helped launch
local awareness of these visit
possibilities in a 2010 study
for Tualatin Historical Society.
His research shows that people
who already live and work in
Tualatin are major hosts for
tourists themselves. As tour
guides and local experts, here is
your own pocket guide on what
to tell your visiting friends and
relatives and where to point out
interesting things to see. For more
information, including a selfguided auto tour, call the Tualatin
Heritage Center.
Lake
Missoula Floods (sometimes called
Bretz floods for an early scientist)
scour large areas of Columbia
River drainage from Canada,
Montana, Idaho, Washington and
Oregon. Experts point to evidence
the floodwaters pushed south
through the entire Willamette,
Tualatin and Yamhill River valleys
with water levels over our city at
more than 300 feet deep.
Large
animals roamed our area, and
after death, were covered by many
feet of soil as the Ice Age ended.
According to oral traditions,
Northwest Indian tribes also called
this region home about this time.
PSU student John George remembered those
tales of “elephants” in Tualatin and needed a science
project. With buddies Ron and Gordon Sund, he
excavates mastodon bones from a marshy area just east
of Martinazzi Street near the
Fred Meyer south driveway.
.
PSU staff give
skeletal bones to Tualatin
City Manager Yvonne
Addington who stores them
in the city shop
City gives bones to
Oregon Zoo
Tualatin
resident and PSU geology
professor Dr. Scott Burns
brings students to his
hometown to observe
rock strata in an Ice Age
gravel pit now covered by
Bridgeport Village and to the
nearbyTonquin “scablands”
scoured by the massive floods
Spurred by citizen
fundraising, Tualatin city
officials arrange for the
University of Oregon to
reassemble skeleton for
display in city library/city hall lobby
City of Tualatin’s Ibach Park opens with Ice
Age interpretive features
John George gives
Tualatin mastodon tusk/
molars he had kept since
1962 for permanent display at
Tualatin Heritage Center
•
•
New Tualatin Library
refurbishes mastodon as its
featured exhibit
Aloha chiropractor
donates “mastodon” sacrum
dug near confluence of Fanno
Creek and Tualatin River for
display at Heritage Center
PSU graduate
student Danny Gilmour
discovers the “mastodon
sacrum” is actually from a
Harlan ground sloth (likely
20 feet long, weighing 3 to 4
tons); University of Oregon
returns 7 bones not used in
the original 1992 library
mastodon exhibit
•
•
•
Lower Columbia
Chapter of the Ice Age Floods
Institute offers first in series
of guided tours of Ice Age
features in the TualatinSherwood area
THS now displays glacial erratics from Tualatin,
Gaston, Scholls, Aurora, I-205 near West Linn, and
southern Washington. Discussions of a possible
“rock garden”are underway.
Busy Tualatin farmers pay little attention to large
“elephant” bones dug up while plowing in rich lowlands
near present-day Fred Meyer.
Gaston resident
Doug Ott sees a Tualatin
Historical Society cable TV
video on Ice Age findings in
Tualatin and invites the key
partners to come see two
possible glacial erratics in his area. Shortly after, local
businessman Brian Clopton agrees to arrange excavation
and hauling them 25 miles to the Heritage Center