Near Ellensburg in Kittitas County, Washington — The American West (Northwest)
Then, this peaceful scene is disturbed by lava welling up from within the earth and rushing across the land. The flow covers tens of thousands of square miles, burying forests, rivers, and swamps. As it cools, the lava solidifies into rock called basalt. Scientific evidence indicates that dramatic events such as these occurred repeatedly between 14 and 18 million years ago.
Beneath your feet are more than fifty lava flows, each having gushed from cracks in the earth more than 100 miles to the east. The uppermost is the Kelly Hollow flow, nearly 200 feet thick here. It continues nearly 200 miles southwest to the Oregon Coast.
As you continue east, watch for the layers of basalt in the road cuts and canyon walls. The remains of the ancient trees entombed in basalt may be viewed at Ginkgo Petrified Forest State Park. Beyond the park, the basaltic cliffs of the Columbia River have been carved by the Ice Age floods.
Erected by Washington State Department of Transportation.
Location. Click for map. The marker is located at Ryegrass Safety Rest Area Eastbound, 9.8 miles east of Exit 115 on Interstate 90. Marker is in this post office area: Ellensburg WA 98926, United States of America.
Other nearby markers. At least 1 other marker is within walking distance of this marker. The Olmstead Place (approx. half a mile away).
Related marker. Click here for another marker that is related to this marker. To better understand the relationship, study the marker shown.
Also see . . .
1. USGS/Cascades Volcano Observatory - Columbia River Basalt Group. (Submitted on November 27, 2010, by PaulwC3 of Northern, Virginia.)
2. The Columbia River Basalt Group - Exposed by the Ice Age Floods. (Submitted on November 27, 2010, by PaulwC3 of Northern, Virginia.)
Categories. • Natural Features •
Credits. This page originally submitted on , by PaulwC3 of Northern, Virginia. This page has been viewed 763 times since then and 24 times this year. Photos: 1, 2, 3. submitted on , by PaulwC3 of Northern, Virginia. This page was last revised on June 16, 2016.
Editor’s want-list for this marker. Photos of the remains of the ancient trees entombed in basalt at Ginkgo Petrified Forest State Park • Can you help?