Ice Age Floods National Geologic Trail
Ice Age Floods National Geologic Trail
Tucked into the scablands near Cheney, Washington, Turnbull National Wildlife Refuge is a living mosaic of what the Ice Age Floods left behind: a landscape of pothole lakes, basalt outcrops, and channeled terrain now teeming with more than 200 species of birds and wildlife. The...
Tucked into the scablands near Cheney, Washington, Turnbull National Wildlife Refuge is a living mosaic of what the Ice Age Floods left behind: a landscape of pothole lakes, basalt outcrops, and channeled terrain now teeming with more than 200 species of birds and wildlife. The refuge's distinctive topography of small lakes, rocky ridges, and wetlands was carved by floodwaters that ripped across this area in braided channels, scouring basalt bedrock in some places while depositing gravel bars in others. The potholes that now serve as nesting habitat for ducks, geese, and shorebirds were excavated by kolks -- powerful underwater vortices that drilled into solid rock like liquid tornadoes. At 6,000 acres, Turnbull preserves one of the most pristine examples of Channeled Scabland terrain anywhere, where the interplay of geology and ecology is on full display. Walking the refuge trails, you move between flood-scoured basalt channels and tranquil wetlands that feel worlds apart but were created by the same catastrophic events. It is one of the best places to see how nature has reclaimed the flood-devastated landscape over 15,000 years.
Open daily; hours 6 a.m.–6 p.m. November through April and 6 a.m.–9 p.m. May through October. A $3 vehicle fee applies seasonally (March–October) on the auto-tour loop; federal Interagency passes are accepted. The 3,300-acre Public Use Area, with more than 10 miles of hiking trails (three accessible), is south of Cheney, Washington, in Spokane County.
The refuge sits on the eastern edge of the Channeled Scablands and exposes the textbook fingerprint of Missoula-flood erosion: stripped basalt surfaces, dry coulees, gravel bars, potholes, and isolated buttes where the floods scoured loess and soil down to the bedrock. The hummocky topography of ponderosa pine over basalt outcrop is essentially flood-stripped channeled scabland that filled with wetlands after the floods ceased. Turnbull is not on a primary flood routeway; it lies in the Cheney–Palouse tract, one of the lateral scabland channels that carried overflow southwest from Spokane out of glacial Lake Columbia and (during earlier events) glacial Lake Missoula. The depth and number of floods through this tract is debated, but field evidence shows repeated flood inundation over the 2 ky leading up to about 14 ka. The wetlands and lakes themselves are post-flood features filling scour basins.
The Balbas et al. (2017) 10Be chronology constrains the main flood pulses through the Cheney–Palouse tract to between 18.2 ± 1.5 ka and roughly 14 ka. No site-specific peer-reviewed updates for Turnbull NWR have appeared since.
The Ice Age Floods Institute's Cheney–Spokane Chapter covers Turnbull and the surrounding scabland. The chapter offers field trips and talks but does not maintain a permanent interpretive presence inside the refuge itself.
Best visited March through May for migrating waterfowl and wildflowers, or September–October for fall color and elk activity. The 5.5-mile Pine Lakes Loop auto tour with several short walking trails provides the most efficient way to see both flood-stripped basalt and the post-flood wetland landscape.
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.