Ice Age Floods National Geologic Trail
Ice Age Floods National Geologic Trail
OMSI sits on the banks of the Willamette River in Portland on ground that was beneath hundreds of feet of floodwater during the Missoula Floods -- a fact that adds geological weight to the museum's mission of inspiring scientific curiosity. When the floods roared through the...
OMSI sits on the banks of the Willamette River in Portland on ground that was beneath hundreds of feet of floodwater during the Missoula Floods -- a fact that adds geological weight to the museum's mission of inspiring scientific curiosity. When the floods roared through the Columbia Gorge and spread into the Portland Basin, they submerged the entire area to depths exceeding 400 feet, creating a temporary lake that stretched from the gorge to the Willamette Valley. The flat terrain on which OMSI and much of Portland's east side is built consists entirely of flood-deposited sediments -- fine silts, sands, and gravels laid down as the turbulent waters slowed and stilled. Founded in 1944, OMSI is one of the nation's leading science museums, and visitors can learn about the floods that shaped the very ground they are standing on. The museum's location on the Willamette, a river whose entire lower valley was reshaped by the floods, makes it a natural starting point for understanding Portland's ice age geography. Look at the city's east side stretching flat to the Cascades foothills: all of that was underwater, deposited by a flood that traveled 500 miles from Montana.
OMSI is open Tuesday–Sunday, 9:30 a.m.–5:30 p.m., at 1945 SE Water Avenue in Portland. The temporary exhibit Heads and Hearts: Seeing the Landscape through Nez Perce Eyes — which addresses Mount Mazama, the Missoula Floods, and other landscape-scale events through Plateau-tribal storytelling — ran January 10 through February 16, 2026 and has since closed. Standard admission applies; OMSI's planetarium and earth-science floor remain the most direct flood-themed touchpoints day-to-day.
OMSI sits on the inside of the Willamette River bend in the Portland basin, terrain that was inundated by Missoula floodwaters at depths exceeding 400 feet during the largest events. The Portland-basin slackwater deposits — the rhythmites that fill much of the Willamette lowland — are visible in road cuts within a few miles of the museum. OMSI's permanent earth-science programming uses the floods as one of the primary stories of Pacific Northwest landscape formation. The site itself is not a primary outcrop; its value is interpretive, not stratigraphic.
The Heads and Hearts exhibit (2026) integrates Indigenous oral history with the cosmogenic flood chronology, drawing on work by geologists Roger Amerman and Ellen Bishop. No new academic publications specific to OMSI's flood programming.
OMSI has an institutional relationship with IAFI's Lower Columbia Chapter, which periodically holds public lectures at OMSI and at Portland-area libraries.
Best visited year-round; allow a half day. The Empirical Theater and planetarium programs occasionally include flood-geology features.
Every site along the trail will receive the full Terrain360 capture treatment: ground-level 360° panoramas, drone aerial imagery, and photogrammetry-based 3D models that visitors can spin in their browser. This page reserves the slots; the imagery flows in as field capture completes.
Ground-level 360° panorama, every step along the feature, captured by Terrain360 field crews.
Drone flyovers reveal the geometry of catastrophe — ripple marks, gravel bars, and scour patterns invisible from the ground.
Photogrammetry and Gaussian-splat models let visitors rotate, measure, and inspect features in detail-page WebGL viewers.
Ice Age Floods National Geologic Trail
The Oregon Museum of Science and Industry (OMSI) in Portland, Oregon, was founded in 1944. OMSI is one of the nation’s leading science museums and a trusted educational resource for communities throughout Oregon and the region. Through museum exhibitions, public programs at the museum and across the region, outdoor programs, traveling exhibitions, digital learning, and learning research and design, OMSI nourishes a lifelong love of science, curiosity and learning for diverse audiences.
OMSI’s mission is to inspire curiosity through engaging science learning experiences, foster experimentation and the exchange of ideas, and stimulate informed action. OMSI’s vision is to collaborate with partners to ignite an education transformation at the intersection of science, technology, and design. We will weave a thriving innovation district into the fabric of Portland that spreads opportunities across the Northwest.
Museum Hours as of Sept 6Tues-Sun 9:30-5:30
Visitor Informationhttps://omsi.edu/visitor-info
Visit us atFacebook,Mastodonand ourYouTube Channel.
Ice Age Floods Institute is a 501(c)(3) tax-exempt non-profit EIN 91-1658221Donations and member fees may be tax deductible