Steamboat Rock lies at the very northern end of the Grand Coulee. At over 1 mile long, ⅔ mile wide, and 800 feet high. The basalt-topped butte standing alone in the middle of the coulee, almost completely surrounded by the waters of Banks Lake is an incredible sight. It was left behind by erosion of both the Ice Age Floods that carved the Grand Coulee, and the Okanogan Lobe of the ice-age continental ice sheet.
Because this area is near the thinning outer margin of the Columbia River Basalt extent, it’s easy to see Columbia River Basalt directly overlying older granitic basement from the trails around the base. A steep climb on a well constructed trail leads to the broad top of Steamboat Rock where the views are truly expansive, encompassing a full 360° panorama. It’s also easy to find granitic erratics and glacial till atop the butte that attest to the fact that the Okanagan Lobe overrode Steamboat Rock during the most recent Ice-Age glacial advance.
The campgrounds at the State Park are spacious and well laid out. There is easy access to both the trails and to Banks Lake for fishing, boating and swimming. Most of the water in Banks Lake has been pumped up from the Columbia River’s Lake Roosevelt, and impounded by a dam 20 miles south at Coulee City. Banks Lake is a key element in the Columbia Basin Project that supplies water for the verdant agricultural areas to the south in an otherwise quite dry, high desert environment.
Some other interesting places to explore in the area include Northrup Canyon, Grand Coulee Dam, and the quixotic Gehrke Windmill Garden just north of Electric City.
