Bighorn Sheep range widely in western Canada, western United States of America (USA), and northern Mexico. In Canada, Bighorn Sheep are distributed throughout the Rocky Mountains in Alberta and British Columbia, south from the Peace River to the Canada-USA border. Two small populations also have been introduced to central British Columbia outside their normal distribution. Populations of the “interior” ecotype, are scattered through central British Columbia. Populations around Kamloops and Granby have been reintroduced, mostly into historically occupied habitat.

In the USA, Bighorn Sheep are widely distributed from Montana and Idaho south to Colorado and New Mexico.  To the south, “desert” bighorn (traditionally O. c. nelsoni, O. c. cremnobates, and O. c. mexicana) inhabit southern portions of California, Nevada, Utah and New Mexico, much of Arizona, and west Texas. To the west, bighorn occur in scattered populations in the Columbia plateau and Great Basin ranges of Washington, Oregon, southwest Idaho, and northern Nevada. East of the Rocky Mountains, bighorn exist in scattered herds in badlands and river-breaks in eastern Montana, North and South Dakota, northeast Wyoming, Nebraska, and outside of historic range in southeast Colorado.

In Mexico, desert Bighorn Sheep were historically distributed in the northern states of Nuevo León, Coahuila, Chihuahua, Sonora, Baja California and Baja California Sur. However, extirpation of Bighorn Sheep later occurred in Chihuahua, Coahuila, and Nuevo Leon.  Through the cooperative efforts of the federal government (SEMARNAT), private landowners, and conservation organizations, desert Bighorn Sheep in Mexico have been restored to five states including: Mexican bighorn (O. c. mexicana) in Chihuahua, Coahuila, and Sonora; peninsular bighorn (O. c. cremnobates) in Baja California; and Weems’ bighorn (O. c. weemsi) in Baja California Sur.

Although protected areas such as National, State and Provincial Parks provide important reservoirs of wild sheep, restoration efforts across North America have been centered on federal, state, provincial and private lands where people live, work and recreate (i.e. working landscapes). 

In Canada, more than 4,500 Rocky Mountain bighorns are fully protected within five National Parks (Banff, Jasper, Kootenay, Waterton, Yoho). Many also receive some level of protection in provincial parks and other protected areas in Alberta and British Columbia. Outside national parks, Bighorn Sheep are covered by provincial or state wildlife acts, and most populations are hunted under license. Harvesting both adult males and adult females is permitted in some populations. Hunting quotas are determined each year, and in general regulations are strictly enforced. Management consists of regulating annual harvests, habitat improvement, annual censuses, translocation of animals, disease surveillance, implementing separation practices between domestic and wild sheep and goats, and promoting research. Between 150 and 200 male and 150 to 200 female bighorns are harvested annually in Alberta. In British Columbia, where only males are hunted: about 100 bighorns are shot each year. In much of Canada, male harvest is limited only by the availability of adult males that have reached a minimum curl size, which can lead to artificial selection against large-horned rams (Pigeon et al. 2016).

In the US, Bighorn Sheep occur on public lands including National Parks, Monuments, Recreation Areas, Wildlife Refuges, lands administered by the U.S. Forest Service and Bureau of Land Management, and on state lands such as state parks and state general land office properties.  In addition, private land provides important bighorn habitat throughout the west. 

Since 1922, 1,460 separate projects conducted by 15 state and two provincial wildlife agencies have resulted in the translocation of more than 21,500 Bighorn Sheep.  This has accounted for much of the recovery of Bighorn Sheep from historic low numbers in the 1960s. While primarily adult males are taken, some states offer adult female hunting opportunities for the purpose of reducing populations. The number of Bighorn Sheep permitted to be taken each year is conservative (1-3%) and is regulated by each state. All states require that the horn of legally-taken males be plugged (horn plugs provided to every jurisdiction by the Wild Sheep Foundation) for permanent identification. This practice allows easy identification of illegally-taken animals and thus discourages poaching.

Improvement of habitat for Bighorn Sheepoccurs on state, federal and private lands.  Projects have been funded with combinations of federal, state, and private moneys. Natural water sources have been improved and artificial water sources created, especially in the Mojave and Sonoran deserts of the Southwest. Further north, dense forest or shrub vegetation has been cleared, often by controlled burning and silvicultural practices, to provide open areas with forage for Bighorn Sheep. Management and research biologists exchange information on Bighorn Sheep in biennial  meetings of the Desert Bighorn Council and  the Northern Wild Sheep and Goat Council. Proceedings of these meetings are published. In addition, the Western Association of Fish and Wildlife Agencies Wild Sheep Working Group  (https://www.wafwa.org/committees_groups/wild_sheep_working_group/) compiles population and harvest data,  coordinates actions and develops strategies for conservation, enhancement, management and research of wild sheep across jurisdictional boundaries in North America.

Private conservation organizations including the Wild Sheep Foundation and their 51 Chapters and Affiliates raise funds for restoration, management and research. At least 14 states auction and/or raffle one or two special bighorn hunting licenses to raise funds for these purposes. Its status within the US is Not Threatened. While much work is yet to be completed, the status of most traditional subspecies and major ecotypes of Bighorn Sheep is satisfactory because of the conservation efforts of state wildlife agencies, private landowners and non-profit conservation organizations. 

Conservation measures proposed for USA: 1) Additional research on pathogen transmission from domestic sheep and goats to Bighorn Sheep, 2) Developing science-based effective separation practices between the two. Bighorn should be separated from contact with domestic sheep and domestic goats in space and time to minimize pathogen transmission. 2) State and federal agencies should coordinate planning efforts to enhance the long-term persistence of the numerous bighorn herds with fewer than 100 sheep. Strategies should include increasing herd size, expanding habitat and increasing herd mobility, and enhancing habitat quality and habitat protection in areas of connectivity between small herds (Bailey 1992). A more thorough understanding of pathogens is vital to this effort, 3) Land management agencies, especially the U.S. Forest Service and Bureau of Land Management, should formally recognize bighorn ranges in their management plans, including areas of connectivity that facilitate movement within and between herds. and 4) establish and expand Bighorn Sheep populations in historic and biologically suitable habitat.

The species in Mexico is currently listed in Appendix II of CITES. The high price ($30,000 to over $100,000) that some conservation-minded hunters are willing to pay has motivated private and communal landowners in Sonora and Baja California to begin desert sheep restoration, enhancement and management programs. Accomplishments in Mexico rival, and in many cases exceed, accomplishments in many of the States and Provinces in the USA and Canada, ultimately leading towards a future downlisting in Mexico.

Future conservation measures for Mexico must include: strategies for addressing habitat loss, degradation, and fragmentation; approaches for mitigating the potential transfer of pathogens from domestic sheep to Bighorn Sheep (effective separation); implementation of effective law enforcement programs; expansion of Mexico university wildlife conservation programs; and development and implementation of public wildlife education programs.