The song of the Canyon Wren (Catherpes mexicanus) is widely recognized but poorly studied. Here we present the first comprehensive description of Canyon Wren song, including data from a focused study in northern Colorado and data from songs recorded across the species' geographic range. Both male and female Canyon Wrens produce a stereotyped contact call and sex-specific song. Females sing infrequently, using a single song type. Males typically sing five song types, all consisting of a descending cascade of notes to which they variably append up to seven broadband notes. Songs are delivered with eventual variety in bouts that include an average of 4.6 repetitions of one song type, with temporal breaks between bouts. In the population we studied most song types were widely shared and males' repertoires overlapped by 94%. Some song types are apparently geographically restricted, while others are sung across large areas of the species' range. Overall, our results suggest that the Canyon Wren's song repertoires are relatively small compared with those of other wrens and that overlap of individuals' repertoires is high. Local and rangewide stability of certain song types may reflect high fidelity of copying during learning, this stability may be favored by ecological and life-history traits including low density of territories, lack of migration, and long-term monogamy.