Mono Basin sage grouse are a subpopulation of greater sage-grouse (Centrocercus urophasianus) that occur on the border of California and Nevada. See Map 2. Geneticists have discovered that Mono Basin sage grouse are genetically distinct from other sage grouse. Research indicates that Mono Basin sage grouse have "a unique history of isolation distinct from all other populations" and that they are "at least as divergent from other populations of the greater sage-grouse as Gunnison sage-grouse are from the greater sage-grouse." (Oyler-McCance et al. 2005: 1308 ). Oyler-McCance et al. concluded that the Mono Basin area population does "certainly qualify as a distinct population segment from a genetic standpoint and may even warrant consideration as a new subspecies." (Oyler-McCance et al. 2005: 1308 ).

Despite their distinct genetic traits, Mono Basin sage grouse appear and behave as other greater sage-grouse, and have the same habitat requirements as other sage grouse. Unfortunately, like other sage grouse populations, Mono Basin sage grouse populations have fallen precipitously since the early 1900s. A species that was once described as abundant now only exists in small, isolated populations in the region. Sage grouse habitat in the Mono Basin area has been degraded and eliminated by livestock grazing; off-road vehicle use; residential development; pinyon-juniper encroachment; invasive species; wildfire; mining; placement and construction of roads, fences and transmission lines; and other forms of land use and development.

Conservation and faith organizations petitioned the U.S. Fish and Wildlife Service to list Mono Basin sage grouse as threatened or endangered under the Endangered Species Act in 2005. Their genetic distinctiveness, combined with their declining population trends, qualify Mono Basin sage grouse for protection under the Endangered Species Act (ESA) as a distinct population segment.