FLOODS & GEOLOGY
Shaping the Valley
Around 12,000 to 17,000 years ago, massive Ice Age floods transformed the Willamette Valley, carrying rocks and sediments across the region. These floods left behind glacial erratics and rich deposits of gravel, silt, and clay that helped create the valley’s fertile soils.
Today, evidence of these ancient floods can still be seen throughout the landscape, while their deposits continue to support the region’s abundant agriculture and renowned vineyards.
DISCOVER THE LANDSCAPE
Explore Amity’s Outdoors
The Fertile Floodplain
The Ice Age floods deposited vast amounts of gravel, silt, and clay that helped make the Willamette Valley an extremely fertile floodplain. As a result, you’ll find one of the nation’s most fertile agricultural areas. Perfect for Pinot Noir, Pinot Blanc, and Pinot Gris grapes!
Erratic Moves
Visit Erratic Rock State Natural Area near Salem to learn more. You can see a 90-ton boulder from the Rocky Mountains deposited by the massive flood force. It is the largest glacial erratic found in Oregon.
TIP: an erratic is a boulder or big rock that has been moved a great distance by a glacier. It sticks out, sort of a sore thumb in the surrounding landscape!
An Ice Age Hitchhiker
Mrs. Ben Maxwell sits atop the Bellevue Erratic in 1960. Carried from eastern Washington by an iceberg during an Ice Age flood, this enormous rock came to rest in the Willamette Valley. Today, visitors can follow a short trail to see it at Erratic Rock State Natural Site near Sheridan.
Salem Public Library Historic Photograph Collections –Ben Maxwell Collection
Follow the Floods
You can visit sites throughout Oregon, Washington, Idaho, and Montana at the National Park Service’s Ice Age Floods National Geologic Trail. The flood region in Oregon includes the Willamette Valley floor from the Portland Basin south to Salem, Corvallis, and Eugene. You can see flood deposits and ice-rafted erratics throughout the region.
INTERACTIVE MAP
Find Your Next Stop
Discover Amity, one stop at a time. Click or tap a marker, then scroll down in the popup and select Learn More to explore that location’s story.