Sediment yield from small arid basins, particularly in the Mojave Desert, is largely unknown owing to the ephemeral nature of these fluvial systems and long recurrence interval of flow events. We examined 27 reservoirs in the northern and eastern Mojave Desert that trapped sediment from small (< 1 km2) drainage basins on alluvial fans over the past 100 yr, calculated annual sediment yield, and estimated the average recurrence interval (RI) of sediment-depositing flow events. These reservoirs formed where railbeds crossed and blocked channels, causing sediment to be trapped and stored upslope. Deposits are temporally constrained by the date of railway construction (1906–1910), the presence of 137Cs in the reservoir profile (post-1952 [...]