Coulee Corridor Scenic Byway
Upper Grand Coulee, WA

900-foot coulee walls contrast sharply with the waters of Banks Lake in this flood-carved coulee that dates from the Ice Age. Here the power of ancient waters is graphically illustrated and reported in the strata of ancient basalt laid down by multiple lava eruptions from millions of years ago and hundreds of miles away. Steamboat Rock, a columnar basalt butte that was once an island in a rerouted Columbia River bed now towers 800 feet above the surface of Banks Lake.