Kettle River Range Mountains, which in turn form part of the Columbia Mountains. The range runs north to south, bordered on the east by the Kettle River and the Columbia River, and on the west by the Kettle River, the Curlew Valley and the San Poil River. The mountainous region begins immediately north of the Canada–US border, at Grand Forks, British Columbia, extending 110 miles (177 km) south to the bend of the Columbia River and Lake Roosevelt, formed by Grand Coulee Dam, where it terminates. The Okanogan Highlands are adjacent to the range on the west, and the Selkirk Mountains are adjacent
Grand Coulee volume of water flowing out of the upper coulee. The distribution begins in the uncanyoned basin below Dry Falls and expanded to over a before reaching Quincy Basin. One cataract (Unnamed Coulee) is high and had three alcoves over more than a . There is no channel as the water arrived in a broad sheet. The gravel deposits of Quincy Basin represent only a third or a fourth of the estimated 11 cubic miles of rock excavated from the Grand Coulee and its smaller other related coulees (Dry, Long Lake, Jasper, Lenore, and Unnamed). Most of the debris was carried