ON-006-26M Alluvial Fan Mapping of Summit County, Colorado (Map) Details The Colorado Geological Survey develops and provides a variety of geologic hazard maps for various state and local governments with land use and hazard mitigation planning in mind. To prepare for post-wildfire natural hazards, the CGS has mapped alluvial fans as well as high-angle fans and (or) debris fans. Areas with these landforms are at risk for debris flows and (or) mudflows, especially after wildfire events. Using available Colorado LiDAR datasets, both known and previously unrecognized alluvial fans were compiled, mapped, and defined. This map is part of a statewide effort to develop county-specific maps of alluvial fans in Colorado. To the map: ON-006-26M Alluvial Fan Mapping of Summit County, Colorado (Map) Download the data as an ArcGIS Pro project package (.ppkx) here: ON-006-26D Alluvial Fan Mapping of Summit County, Colorado (Data) – v20251121 Citations Crandall, Amy, King, Grace, Lindsey, K.O., Zhou, Wendy, Fitzgerald, F.S., and Lovekin, J.R., 2025, Alluvial fan mapping of Summit County, Colorado (map): Colorado Geological Survey Online Series 006-26M. https://coloradogeologicalsurvey.org/publications/alluvial-fan-map-summit-colorado/