Tualatin Ice Age Trails



“Elephants used to live here in Tualatin, son”,  Tualatin’s old Marshall, Charlie Roberts, told the curious young John “Bobby” George in the early 1940’s.  ” That big ugly bone I’m using for a door stop is an ancient elephant’s molar found in the Tualatin swamps a few years back.”


John was certain the Marshall had too much to drink.  Year’s later. in 1962, as a Korean veteran, John, who became a dentist,  needed an easy project for a Portland State University geology class.  He told Dr.John Wirth he was going to dig up a mastodon skeleton in the Tualatin Swamps– and he did.  At the time, I had an “at home” secretarial service in my hometown of Tualatin and I typed John George’s PSU paper.

In the early 1970s, as Tualatin city manager, I saw John’s mastodon bones displayed at PSU as the “Tigard Mastodon”.
 Knowing it came from Tualatin, I was irritated and ask PSU to correctly call it the “Tualatin Mastodon”.
 PSU’s Dr. Wirth said,  “We don’t have room for it right now, would you like it back in Tualatin?”.
 I’m not sure why, but I accepted.  It came in a pine box- and I asked the public works crew to store it and not touch it.
 They marked it “Yvonne’s skeleton in the closet”.
 After I left city employment in  1982, the city gave it to Portland Zoo which did nothing to put it together.  In 1990, Tualatin’s historian Loyce Martinazzi asked for it back and citizens and children raised funds to put the skeleton together in a partial display in the Tualatin library.
University of Oregon professors Lindner and William Orr put one side of the skeleton found back together.  I met John George for the second time when a dedication was held in 1992.  Just a few years ago, the city remodeled the library and gave the Tualatin Mastodon a prominent place in front of a glass etching.  The library patrons, which number 1000 per day, get a chance to see some real Tualatin ice age history.

1.Recent video productions:  Click on the following sites to see recent video productions of interest to

Ice Age enthusiasts:

1. (Coming soon:  Grant’s Getaways-Oregon Erratic Rocks (KGW TV, Oregon Travel)
2.  (Coming soon:  Grant’s Getaways-Ice Age Tonquin Trail)
3.  (Coming soon:  Mike Full’s Wooly mammoth tracks prove beasts once roamed Oregon)
4.  (Coming soon:  Scott Burns interview on Tualatin Chamber of Commerce website regarding local impacts of Ice Age Floods.)

2. New Ice Age Time Travel book released

“Terra Tempo, The Four Corners of Time” written by Portland’s David Shapiro has just been released. It is a time travel  adventure for all ages. The first book released in 2011 was about the Missoula Floods.  This one takes place on the Colorado Plateau.  Story and illustrations are superb.  David presented a video of  researching and making the book at a recent joint meeting of the Tualatin Historical Society/Ice Age Floods Institute.

3.  Upcoming and exciting meeting of interest:

“Mike Full, McMinnville’s expert and successful Scuba Diver for ancient animal bones, will be key speaker at a joint meeting of the Tualatin Historical Society and Ice Age Floods Institute, Lower Columbia River Chapter on Thursday, February 21, 7:00 PM at Tualatin Heritage Center, 8700 SW Sweek Drive (next to Police Dept.)   He will show specimen’s collected including baby mammoth teeth found in Yamhill River last summer.

Also on the agenda will be David Ellingson, Woodburn science teacher and successful antiquess bison bones discover.  He and his students who also dig the fossils will present portable displays of  ancient animal bones, seeds, and other small animal bones to the Historical Society to loan to the Tualatin library and schools.

The Public welcome to all meetings held on third Thursday of each month.

4.  Ice Age “branding” and things to see and do. The Tualatin Historical Society with the help of local City and County officials and Chambers of Commerce have been successful in persuading the Metro Regional Government to rename a proposed 22 mile bicycle/walking trail between Wilsonville, Sherwood and Tualatin, the “Ice Age Tonquin Trail”.  The renaming will eventually put the “ice age”  area on travel maps, GPS, GIS systems and should help identify the area as greatly impacted and benefitted by the ancient floods in the rich Willamette River Valley and its tributaries of the Tualatin and Yamhill River Valleys over 12,000 years ago.

The Tualatin Historical Society received a grant from Washington County Visitor’s Association to develop and start branding a Tualatin Ice Age Visitor’s Plan for economic development/jobs, historical,cultural and educational purposes.

A second grant was given to the Tualatin Chamber of Commerce to enhance their website for ice age branding and getting people to stop off at Tualatin restaurants, motels, stores, etc from I-5, I-205, 99W,and  Tualatin-Sherwood road from I-5;   leading to other visitor attractions on their way to the Pacific Ocean.

A third grant received this year by the City of Tualatin is to lay out Ice Age “things to see and do” that are educational, historical, healthful and which allows Tualatin to design another Tualatin Ice Age Discovery Trail which will further connect to the Ice Age Tonquin Trail and other trails in the area.

Before John George passed away in March 2010, he gave me, as the President of  the Tualatin Historical Society, the mastodon tusk and two molars he had kept and asked me to carry on his legacy.
 They are on display at the Tualatin Heritage Center as are 6 more bones of the mastodon found by Danny Gilmour, another PSU graduate, in a U of O storage room. They are on loan from U. of O.  In 2009, Dr. Robert McDonald, an Aloha chiropractor, gave the Historical Society the sacrum of an ancient Harlan’s ground sloth found about 1972 near Fanno Creek and the Tualatin River.  And in 2009,mammoth bones were located in and near Cipole Swamp.
 Dr. Lyle Hubbard  and Mike Full identified and made a poster of 6 Tualatin Mastodon Bones left at U of O following construction of display in 1992.   Danny Gilmour had rediscovered the bones and U of O has loaned them for display at the Tualatin Heritage Center.
Rocks were always of interest to me and my family.  I had a rock collection at 10 and my dad, to keep us kids quiet in the car going up the Columbia River highway, always made us look for the three types of rocks–igneous, sedimentary and metamorphic.  I had no idea I would find myself adding to Marshall Charlie Roberts story by now saying that gigantic floodwaters from Canada/Montana brought huge erratic rocks in melting icebergs to the Tualatin area over 15,000 years ago at the end of the ice age.   The floods were 350′ deep and covered most of the area  several times.
Tualatin’s Koller Kolk Pond,  a part of Ice
Age Tonquin Scablands,  a result of the Great
Missoula Floods in Tualatin Area
They are tough stories to believe, so recently the Tualatin Historical Society, Chamber of Commerce and City of Tualatin have decided to educate residents and visitors about Tualatin’s unique history and work on a Tualatin Ice Age Visitors Plan funded for economic development/job purposes by the Washington County Visitor’s Assn.   It calls for better signage, replicas, art work, an Ice Age Trail beginning near the Tualatin swamps at Fred Meyers where the mastodon was found and goes around the town; perhaps an Ice Age Museum!.
In late 2011,with the help of Brian Clopton of Clopton Excavting, we moved from a Gaston farm, a 10 ton granite erratic (rock that doesn’t belong there) and a 2.5 ton quartizite to the Tualatin Heritage Center.  They had been left high on a hill by one of the floods in a melting iceberg.
Yvonne Addington & Grant McOmie
with 10 ton Granite Missoula Floods Rock
Moved from Gaston, OR  to Tualatin Heritage Center 
                     — December 29, 2011
So let me try the Tualatin story on you: “Elephants, mastodons, ground sloths, mammoths once lived here in the Tualatin area- also the crawfish–  and before that, huge icebergs in gigantic floods, brought lots of huge boulders here from the Canadian/Montana border over  2,000 miles away!”  The story is featured on Grant McOmie’s  “Grant’s Getaway”  and you can view it at: