Lewis and Clark's Columbia River
Lewis & Clark's Columbia River - "200 Years Later"
"Missoula Floods ... Glacial Erratics"
Includes ... Glacial Erratics ... Missoula Floods ...
Image, 2018, Glacial Erratic, Vancouver, Washington, click to enlarge
Click image to enlarge 		Missoula Flood Glacial Erratic, Vancouver, Washington. This erratic was found in field near 162nd Avenue and now "on display" in a forgotten corner near the Greenhouse, Washington State University, Vancouver Campus. Image taken July 1, 2018.


Glacial Erratics ...
(to come)

Missoula Floods ...
[More]


Missoula Flood Glacial Erratics

  • Clark County, Washington ...
    • 162nd Avenue ...
    • WSU Vancouver ...
    • Ridgefield NWR ...
  • Multnomah County, Oregon ...
    • Lewis & Clark College ...
  • Wasco County, Oregon ...
    • Mosier ...
  • Yamhill County, Oregon ...
    • McMinnville ...


Clark County, Washington ... Washington State University Vancouver Campus ...
Numerous erratics glacial erratics were ice-rafted and deposited in the Vancouver Basin, Clark County, Washington. Four are "on display" at the Washington State University's Vancouver Campus. One is tucked in a forgotten corner near the Greenhouse, and the other three are located on a slope on the east side of campus. All of the erratics are not in their original location. One was found in a field in east Vancouver, and the other three (which use to be one big erratic) were moved after originally being unearthed during construction of the Science building.

Erratic found in east Vancouver, near 162nd Avenue:

"It all started the winter of 2003, when a flash of white caught a WSU graduate student’s attention as he drove along 162nd Avenue in east Vancouver. Investigating further, he quickly realized he was looking at a granite Missoula Ice Age Flood erratic. The boulder, roughly the size of a park bench, had black and white speckles characteristic of the granite in northern Idaho. This area is made up of basalt, not granite. So granite would have been transported by the Missoula Ice Age Floods.

The rock was salvaged from the field where a housing subdivision was being graded and a road was being widened on 162nd Avenue. A small crew of county workers used an excavator to hoist the rock, swinging it onto the back end of a flatbed trailer. The county gave the historic rock to WSU Vancouver for display. It is now located on the east side of the Engineering Building near the entrance to the greenhouse."


Source:    "waymarking.com" website, 2018, "WSU's Missoula Ice Age Flood Erratic, Vancouver, Washington.


Erratic(s) found at the Science Building:

"Missoula flood ice-rafted erratics:   Latitude: 45°43'57", Longitude: 122°37'54", Lithology: Granitic, Comments: Three > 3-foot- (1 meter) diameter boulders, derived from a single large erratic found during excavation of Washington State University Science building; original location 45°43'57", 122°38'04"."


Source:    O'Connor, et.al., 2016, U.S.G.S. Scientific Investigations Map 3357


Image, 2018, Glacial Erratic, Vancouver, Washington, click to enlarge
Click image to enlarge 		Missoula Flood Glacial Erratic, Vancouver, Washington. This erratic was found in field near 162nd Avenue and now "on display" in a forgotten corner near the Greenhouse, Washington State University, Vancouver Campus. Image taken July 1, 2018.

Image, 2018, Glacial Erratics, Vancouver, Washington, click to enlarge
Click image to enlarge 		Missoula Flood Glacial Erratics, Vancouver, Washington. Washington State University, Vancouver Campus. These erratics (originally one large one) were uncovered during construction of the Science Building. Image taken July 14, 2018.
Image, 2018, Glacial Erratics, Vancouver, Washington, click to enlarge
Click image to enlarge 		Missoula Flood Glacial Erratics, Vancouver, Washington. Washington State University, Vancouver Campus. These erratics (originally one large one) were uncovered during construction of the Science Building. Image taken July 14, 2018.
Image, 2018, Glacial Erratics, Vancouver, Washington, click to enlarge
Click image to enlarge 		Missoula Flood Glacial Erratics, Vancouver, Washington. Washington State University, Vancouver Campus. These erratics (originally one large one) were uncovered during construction of the Science Building. Image taken July 14, 2018.
Image, 2018, Glacial Erratics, Vancouver, Washington, click to enlarge
Click image to enlarge 		Missoula Flood Glacial Erratics, Vancouver, Washington. Washington State University, Vancouver Campus. Image taken July 14, 2018.

N45o 43' 56.5"
W122o 37' 58.4"
Image, 2018, Glacial Erratics, Vancouver, Washington, click to enlarge
Click image to enlarge 		Missoula Flood Glacial Erratics, Vancouver, Washington. Washington State University, Vancouver Campus. Image taken July 14, 2018.


Clark County, Washington ... Ridgefield National Wildlife Refuge, Carty Unit ...
There is a Missoula Flood glacial erratic buried in the field at the Carty Unit of the Ridgefield National Wildlife Refuge, Ridgefield, Washington. ["waymarking.com" website, 2018]

Image, 2018, Glacial Erratic, RNWR Carty Unit, Vancouver, Washington, click to enlarge
Click image to enlarge 		Missoula Flood Glacial Erratic, Ridgefield NWR, Carty Unit, Ridgefield, Washington. Image taken October 18, 2018.
Image, 2018, Glacial Erratic, RNWR Carty Unit, Vancouver, Washington, click to enlarge
Click image to enlarge 		Missoula Flood Glacial Erratic, Ridgefield NWR, Carty Unit, Ridgefield, Washington. Image taken October 18, 2018.

N45o 49' 52.9"
W122 o 44' 59.2"


Multnomah County, Oregon ... Lewis & Clark College ...
According to Minervini, et.al., 2003, USGS OFR-03-408, as of June 2003, the U.S. Geological Survey's Missoula Flood Glacial Erratic database contained "records of 400 glacial erratics and their locations; however, approximately 28 of these locations are thought to be duplicates".

Image, 2014, Granitic Erratic, Lewis and Clark College, Portland, Oregon, click to enlarge
Click image to enlarge 		Granitic Erratic, Lewis & Clark College, Multnomah County, Portland, Oregon. Image taken August 24, 2014.
Image, 2014, Granitic Erratic, Lewis and Clark College, Portland, Oregon, click to enlarge
Click image to enlarge 		Granitic Erratic, Lewis & Clark College, Multnomah County, Portland, Oregon. Image taken August 24, 2014.
Image, 2014, Granitic Erratic, Lewis and Clark College, Portland, Oregon, click to enlarge
Click image to enlarge 		Granitic Erratic, Lewis & Clark College, Multnomah County, Portland, Oregon. Image taken August 24, 2014.

A GRANITIC ERRATIC
CARRIED BY AN ICE-BERG
AT THE END OF THE LAST
ICE AGE FROM THE UPPER
COLUMBIA RIVER BASIN
TO NEAR THIS POINT.


Wasco County, Oregon ... Mosier ...
At Mosier, Oregon, Missoula flood waters spilled over the divide from the Columbia River to Mosier Creek. West of town are nice examples of a glacial erratic and a Missoula Flood eddy bar.

According to Waitt, et.al., (2009):

"West of The Dalles and Rowena Gap we pass the town Mosier in a sysclinal valley. Like the bars at Petersburg and Fairbanks, Missoula flood flow spilling over a divide from Columbia River to Mosier Creek deposited a large delta of southwest-dipping foresets of cobble-pebble gravel and sand." [Waitt, et.al., 2009]

Image, 2018, Glacial erratic in gravel pit, Mosier, Oregon, click to enlarge
Click image to enlarge 		Glacial erratic, Mosier, Oregon. Image taken June 6, 2018.
Image, 2018, Glacial erratic in gravel pit, Mosier, Oregon, click to enlarge
Click image to enlarge 		Glacial erratic, Mosier, Oregon. Image taken June 6, 2018.

The Mosier erratic most likely was rafted in from Canada, is 6x8x12 feet in size, and weighs between 30 to 40 tons.


Yamhill County, Oregon ... McMinnville ...
"This 90-ton rock was deposited during an Ice Age flood. It floated over 500 miles in an iceberg 12,000 to 17,000 years ago, by way of the Columbia River. When the ice melted, the rock was left behind. This is the largest glacial erratic found in the Willamette Valley. It is a type of rock not normally found in Oregon because it came from the Northern Rocky Mountains. Visitors at Erratic Rock can look out across the vast landscape and imagine the huge amount of water that filled the Willamette Valley during the Ice Age Floods."


Source:    "OregonStateParks.org" website, 2018, Erratic Rock State Natural Site.


The "Sheridan Erratic", often called the "Bellevue Erratic", is located on the west side of the Willamette Valley, just off of Oregon Highway 18, and halfway between the Oregon communities of Sheridan and McMinnville. According to Dr. Jim O'Connor in an interview with the Yamhill Valley News-Register" (2005):   "the 90-ton rock, which sits atop a rise about a half mile from the site entrance, probably came in on an iceberg around 15,000 years ago, transported by one of the Missoula floods, the biggest known fresh water floods in history. The erratic rock is at an elevation of 300 feet and the floods probably topped that by 100 feet."

The News-Register goes on to say:   "More than 400 ice-rafted rocks have been identified along the flood plain ... they are different in composition from the local bedrock, thus are called "erratic" and the one near Sheridan is the largest known glacial erratic in the Willamette Valley."

Geologically the rock is an argillite boulder from Canada and is believed to be 600 million years old. It was originally part of the sea-floor. It once weighed 160 tons and measured nearly 21 x 18 x 5 feet. Today the boulder sits in many pieces with the largest being nearly 18 x 13 x 5 feet, and weighs in at 90 tons. Vandalism and souvenier hunters have taken the rest.

The Erratic Rock State Natural Site was purchased from the site's private owners in 1956.


Image, 2013, Glacial Erratic, McMinnville, Oregon, click to enlarge
Click image to enlarge 		Sign, Glacial Erratic, McMinnville, Oregon. Image taken January 11, 2013.
Image, 2013, Glacial Erratic, McMinnville, Oregon, click to enlarge
Click image to enlarge 		Glacial Erratic, McMinnville, Oregon. Image taken January 11, 2013.
Image, 2013, Glacial Erratic, McMinnville, Oregon, click to enlarge
Click image to enlarge 		Glacial Erratic, McMinnville, Oregon. Image taken January 11, 2013.
Image, 2013, Glacial Erratic, McMinnville, Oregon, click to enlarge
Click image to enlarge 		Glacial Erratic, McMinnville, Oregon. Image taken January 11, 2013.
Image, 2013, Glacial Erratic, McMinnville, Oregon, click to enlarge
Click image to enlarge 		Glacial Erratic, McMinnville, Oregon. Image taken January 11, 2013.


From the Journals of Lewis and Clark ...

Clark, ...
 



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*River Miles [RM] are approximate, in statute miles, and were determined from USGS topo maps, obtained from NOAA nautical charts, or obtained from the U.S. Army Corps of Engineers website, 2003

Sources:
  • Minervini, J.M., O'Connor, J.E., and Wells, R.E., 2003, "Maps showing inundations depths, ice-rafted erratics, and sedimentary facies of late Pleistocene Missoula Floods in the Willamette Valley, Oregon", U.S. Geological Survey Open-file Report 03-408;
  • O'Connor, J.E., Cannon, C.M., Mangano, J.F., and Evarts, R.C., 2016, Geologic Map of the Vancouver and Orchards Quadrangles and Parts of the Portland and Mount Tabor Quadrangles, Clark County, Washington, and Multnomah County, Oregon, U.S. Geological Survey Scientific Investigations Map 3357;
  • "OregonStateParks.org" website, 2018;
  • Waitt, R.B., Denlinger, R.P., and O'Connor, J.E., 2009, "Many monstrous Missoula floods down Channeled Scabland and Columbia Valley", IN: "Volcanoes to Vineyards", Geological Society of America, 2009;
  • "Waymarking.com" website, 2018;


All Lewis and Clark quotations from Gary Moulton editions of the Lewis and Clark Journals, University of Nebraska Press, all attempts have been made to type the quotations exactly as in the Moulton editions, however typing errors introduced by this web author cannot be ruled out; location interpretation from variety of sources, including this website author.
/Regions/Places/glacial_erratics.html
July 2018