Crowsnest Pass comprises a valley running east-west through Crowsnest Ridge. On the Alberta side, the Crowsnest River flows east from Crowsnest Lake, eventually draining into the Oldman River and ultimately reaching Hudson Bay via the Nelson River. Summit Lake on the British Columbia side drains via three intermediary creeks into the Elk River, which feeds into the Kootenay River, and finally into the Columbia River to the Pacific.