Riparian corridors in the western United States harbor diverse biological communities that are threatened by reductions in available freshwater, changes to natural disturbance regimes, and anthropogenic disturbances. Limited data are available about bat roosts in riparian habitats in the southwestern United States. We examined day roosts of 3 sympatric Myotis species, the southwestern myotis (Myotis auriculus), Arizona myotis (Myotis occultus), and Yuma myotis (Myotis yumanensis), along the Mimbres River in southwestern New Mexico. We tracked 3 M. auriculus, 3 M. occultus, and 1 M. yumanensis to 16 Fremont's cottonwoods (Populus fremontii), 2 velvet ash (Fraxinus velutina), and 1 Arizona walnut (Juglans major) within the floodplain. Roost trees generally had a greater diameter and greater likelihood of exhibiting fire damage than nearby trees. Moreover, several roosts were in tree species not previously known to be used by these bat species, and bats did not roost in human-made structures in this arid riparian corridor.