Collins View Geological Facts

Was Collins View once an Island?

Collins View Facts: An oceanic island that attached itself to North America is the thirty-six to fifty million years old bedrock Waverly Heights Basalt under Collins View. The basalt is under silt in Collins View. Go to Elk Rock Island in the Willamette River to see the exposed Waverly Heights lava, according to Portland Hill Walks by Laura O. Foster. Two volcanoes, Mount Sylvania and Cook's Butte, are in our Tryon Creek watershed. About 15,000 years ago, the Missoula Floods inundated the Columbia River basin and the Willamette Valley. Did Collins View revert to its island nature then?

The elevation of Collins View averages 423 feet; the crest of 2nd Ave is about 540 feet. The Missoula flood level in Portland and Oswego is estimated to have been 400 feet deep. At elevations above 300 feet in the Tryon Creek watershed, wind- blown silt covers the lava bedrock, while at lower elevations sand and gravel cover it.