The primary purpose of this report is to describe the background information, methods, and results of a surficial geology inventory within the North Cascades National Park Service Complex (NOCA). This is one of twelve basic inventories called for in the National Park Service (NPS) National Resource Challenge. A secondary goal is to provide an overview of bedrock geology, climate, and hydrology as they affect landform processes. The study area for this report is the Stehekin River Watershed, which includes the main Stehekin River and its tributaries Boulder, Bridge, Flat, Maple, McAlester, Park, and Rainbow Creeks.