We have mapped alluvial fans in Death Valley, California using NASA's 8--12 &mgr;m six-channel airborne Thermal Infrared Multispecrtral Scanner (TIMS). We are able to recognize both composition and relative age differences. Age unit boundaries are generally consistent with those obtained by conventional mapping. Composition was verified by field investigatin and comparison with existing geologic maps. Bedrock and its young derived fan gravels have similar emissivities. The original composition of the fans is modified by differential erosion and weathering, permitting relative age mapping with TIMS.