Ice Age Floods National Geologic Trail
Ice Age Floods National Geologic Trail
From the top of the 125-foot Astoria Column on Coxcomb Hill, you look out across the mouth of the Columbia River -- the place where the largest floods in North American history finally emptied into the Pacific Ocean. During the Missoula Floods, an estimated 386 million cubic...
From the top of the 125-foot Astoria Column on Coxcomb Hill, you look out across the mouth of the Columbia River -- the place where the largest floods in North American history finally emptied into the Pacific Ocean. During the Missoula Floods, an estimated 386 million cubic feet of water per second roared down the Columbia, carrying icebergs, boulders, entire forests, and billions of tons of sediment to the sea. The floods deposited such enormous volumes of material on the continental shelf that the submarine deposits have been mapped for hundreds of miles offshore. During glacial maximum, the coastline was more than 25 miles west of its present location, so the floods traveled even farther before reaching the ocean. The Astoria Column's spiral frieze tells the story of the region's human history, from Native Americans to Lewis and Clark, but the geological story dwarfs them all: this river mouth was the exhaust pipe of a 500-mile-long flood system that drained an area the size of Montana in a matter of days. Climb the 164 steps inside the column and look west to see where the continent's most violent geological story ends and the Pacific begins.
The Astoria Column sits atop Coxcomb Hill in Astoria, Oregon, and is open daily 5 a.m. to 10 p.m. The grounds and the climb to the observation platform (164 steps) are free; parking is $10 per vehicle and is valid for one year. The gift shop generally operates 10 a.m. to 5 p.m. (call ahead at 503-325-2963 to confirm).
Astoria sits near the Pacific outlet of the Columbia River, the terminus of the flood pathway. Missoula floodwaters — hundreds of feet deep upstream and still substantial in the Columbia estuary — passed Astoria on their way out to sea, spewing sediment onto the Astoria submarine fan as far south as offshore California. The column itself is not on a flood-deposit feature; its sgraffito mural narrates Pacific Northwest history (Lewis and Clark, railroads, settlement) rather than geology. The 600-foot view from the platform, however, takes in the lower river and the broad estuary that channelled the last reaches of every Missoula flood. Treat this as a context/overview stop rather than a stop where flood landforms are visible at your feet.
No updates found since Balbas et al. (2017), which anchors the largest floods at ~18.2 ± 1.5 ka. Sediment-fan studies of the Astoria fan that bear on flood discharge volumes were summarized in O'Connor et al. (2020), the USGS/ScienceDirect "Missoula and Bonneville floods" review.
No dedicated Astoria Column page on iafi.org. The site falls within the geographic coverage of IAFI's Lower Columbia Chapter (Willamette Valley and lower Columbia River, northwest OR). No specific interpretive panel about the floods is documented at the column.
Best season is spring through fall for clear estuary views; summer can draw crowds and parking pressure. The walk up Coxcomb Hill and the climb to the platform combined take roughly an hour; the column is best paired with the Columbia River Maritime Museum or Lewis and Clark NHP for full regional context.
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.