Depot Creek begins at an unnamed lake Whatcom County, Washington State, United States, located in a cirque between Mount Redoubt and Mount Spickard. The creek exits the lake and flows northwest into a large, swamp-like area at the top of Depot Creek Falls. The creek then drops over the falls and reaches the bottom of the valley. From here the creek flows northwest, passes into British Columbia, Canada, and reaches its mouth at Chilliwack Lake near the lake's south end. Chilliwack Lake flows via the Chilliwack River and the Fraser River to the Pacific Ocean. The portion of the creek in the United States is in North Cascades National Park; the lower creek and creek mouth in Canada are within Chilliwack Lake Provincial Park.