Abstract This chapter presents a method by which morphometric criteria can be used to obtain a rapid first-approximation of potential debris flow hazard on alluvial fans in the Canadian Rocky Mountain Front Ranges. Geomorphic and sedimentologic evidence indicates that many fans are affected by debris flow processes. Such fans generally are steeper than 4° and have small, steep first- or second-order drainage basins with Melton’s ruggedness number ( R ) more than 0.25 to 0.3. Fans not prone to debris flows are dominated by fluvial processes and have gentler slopes in less rugged third-order or higher drainage basins. This morphometric approach should have wide applicability for continuously graded basins in unglacierized regions.