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 ). Geneticists even noted that the Mono Basin population may warrant consideration as a new subspecies of sage-grouse." (Oyler-McCance et al. 2005 ).

Aside from 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, 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; roads; fences; transmission lines; and other forms of land use and development.

The U.S. Fish and Wildlife Service determined that the genetically distinct and geographically isolated Mono Basin sage-grouse qualifies for separate consideration for protection under the Endangered Species Act. Now known as the "Bi-State Distinct Population Segment of greater sage-grouse," the agency declared the Mono Basin birds a candidate for listing in 2010. Unfortunately, candidate status conveys no formal protection to Mono Basin sage-grouse and harmful land uses may continue to threaten the population.