The biology of this species is poorly known. It occurs in a variety of wooded habitats including especially ponderosa pine forest, pinyon-juniper woodland, riparian woodland, encinal (oak woodland), pine-oak woodland, and fir forest. Others come from more arid habitats, including desert shrub, mesquite grassland with scattered oaks, xeric scrub, and tropical deciduous forest. The species is a highly adapted insect predator using a sophisticated combination of sonar signals and flight maneuvers to forage for and intercept its nocturnal prey. It feeds on small moths; other known prey include soldier beetles, dung beetles, leaf beetles, roaches, and flying ants (Wilson and Ruff 1999).
Habitat is primarily mountainous wooded areas (e.g., ponderosa pine, pinyon-juniper, Mexican woodland, oak brsuh) but also includes riparian (e.g., cottonwood) woodland and ranges from Mohave desert scrub of low desert ranges to white fir forest (Hoffmeister 1986). Typically this bat is found near rocks: cliffs, boulders, lava flows, etc., and it is frequently netted along streams or over ponds. Maternity colonies of 30 to 150 individuals have been found in mine shafts, boulder piles, sandstone crevices, lava beds, and beneath the loose bark of large ponderosa pine snags (Bat Conservation International, Western Bat Working Group, Czaplewski 1983, Rabe et al. 1998, Adams 2003).

This species occurs from Distrito Federal and Michoacan (Mexico) to south Utah and south Nevada (USA) (Simmons 2005). The range encompasses the southwestern United States and part of Mexico, from southern Utah and southern Nevada south through Arizona (northwestern, central, southeastern; Hoffmeister 1986) and New Mexico (Mogollon Plateau and western Soccoro County in the San Mateo and Magdalena mountains (Frey 2004) to Distrito Federal and Michoacan in southern central Mexico (Simmons, 2005), including the Sierra Madre Occidental, Sierra Madre Oriental, and Sierra Volcanica Transversal. The range closely approaches California and Colorado, but as of 2005 no records were available for those states. The winter range is not known. The elevational range extends from 403 to 3,225 meters, with most records at 1,100-2,500 meters. Subspecies hualapaiensis: southern Nevada, southern Utah, and northern Arizona (Mohave County and Coconino County north of the Grand Canyon); subspecies phyllotis: remainder of range (Tumlison and Douglas 1992).

At least four protected occurrences exist in Utah: Canyonlands National Park, Capitol Reef National Park, Glen Canyon National Recreation Area, and Natural Bridges National Monument (George Oliver pers. comm., 1998), and at least a few additional protected occurrences are in Arizona (e.g., Grand Canyon National Park) and New Mexico. Occurrences in several national forests and in national wildlife refuges do not necessarily result in much protection for this species. Increased efforts are needed to improve our knowledge of the distribution and abundance of this species throughout its range.Most aspects of the ecology of this species need further study.