The Rocky Mountain Bighorn Sheep in Arizona is truly one of the great conservation stories in Arizona. Once thought to be extirpated from the state a small remnant population was discovered near Morenci in 1957. Through conservation efforts this small population now numbers approximately 1300 sheep and can be found in several of the state’s “sky islands” and highland river canyons. The recovery of the Rocky Mountain Bighorn Sheep has been so successful that they have been used to augment other populations in other states, most notably Antelope Island in Utah.
The recovery of the Rocky Mountain Bighorn Sheep in Arizona is a powerful testament of the resiliency of the Rocky Mountain Bighorn Sheep, dedication of conservations organizations including the Arizona Game and Fish Department, Wild Sheep Foundation and Arizona Desert Bighorn Sheep Society, evolving sophistication of conservation science, and the necessity of interstate, multi-sector collaboration. From the near-extirpation of the species by the mid-20th century, to today’s stable and thriving core herds in eastern and central Arizona, this journey has involved decades of careful reintroduction, vigilant management, and innovative habitat stewardship.
Starting in the 1950s, Arizona Game and Fish Department (AZGFD) and conservation partners began to implement bighorn sheep management and restoration strategies across the state. While initial efforts in the 1950s focused on desert bighorn sheep, by the late 1970s and into the 1980s, attention expanded to include the Rocky Mountain Bighorn Sheep subspecies.
The first formal reintroduction project for the Rocky Mountain Bighorn Sheep in Arizona occurred in 1979. This landmark event sought to establish new herds or augment depleted populations, primarily using animals sourced from healthy herds in Colorado and New Mexico—states with strong bighorn populations and established capture programs. Capture operations typically involved net-gunning sheep from helicopters or using ground-based drive traps in rugged canyon terrain, with intensive veterinary oversight to minimize injury and ensure only healthy, disease-free animals were used.
Subsequent translocation efforts continued periodically into the early 2000’s as AZGFD and partners responded to natural declines and management challenges in both source and recipient herds. New release areas were selected in consultation with experts, often focusing on reclaimed or underutilized habitat within historical range—especially those areas where livestock grazing had been reduced or eliminated and habitat restoration had taken place.
Arizona’s Rocky Mountain Bighorn Sheep populations are concentrated in the high-elevation canyons, cliffs, and river drainages of the state’s east and northeast. Unlike desert bighorn sheep, which are adapted to lower, arid environments and are more widely distributed throughout central and western Arizona, the Rocky Mountain subspecies occupies a mosaic of mountain ranges, riparian corridors, and rugged uplands.
The core distribution areas of Rocky Mountain Bighorn Sheep in Arizona include:
Eagle Creek and Morenci Mine Region: This landscape epitomizes the complex intersection of conservation, industrial activity, and wildlife management. The Morenci Mine, among the world’s largest copper mines, spans over 61,700 acres and operates year-round. The rugged terrain surrounding the mine, along with adjacent Eagle Creek and its associated canyons, provides critical sheep habitat. Area sheep often move between undisturbed public land, lands reclaimed by mining operations, and the edges of urban zones in Morenci and Clifton.
Beginning in the 1970s, surplus Rocky Mountain Bighorn Sheep from the mining areas around Morenci and Eagle Creek, where populations sometimes exceeded local ecological or management carrying capacities, were captured and transplanted to boost or establish herds in other zones such as the Black River, South Fork, and Hellsgate Wilderness.
Clifton Ranger District: Managed by the U.S. Forest Service as part of the Apache-Sitgreaves National Forests, this extensive district comprises both secure mountain wilderness and accessible riparian areas. Bighorn sheep are regularly observed throughout steep cliff faces and along watercourses, particularly in remote sections where livestock grazing is tightly managed or excluded.
Blue River and San Francisco River Corridors: These drainages form crucial migration and dispersal routes, linking sub-populations and allowing genetic exchange. They offer lambing grounds and escape terrain, ensuring long-term population persistence.
Black River and South Fork: Individuals from Blue River and Eagle Creek foundation stocks have naturally dispersed into the Black River corridor. A particularly notable effort, beginning in 2014, involved the direct translocation of over 48 RMBS from Morenci Mine into the South Fork Little Colorado River in northern Unit 1, following habitat improvements post-Wallow Fire and livestock management changes.
West Clear Creek–Hellsgate Wilderness: Initial populations in this highly dissected central Arizona terrain were heavily supplemented or founded outright via translocation from the Eagle Creek region in the late 20th and early 21st centuries. Continued natural expansion, documented via GPS-collaring and tracking, has shown movement into the Mazatzal Wilderness and points west and east.
Black Mesa–Parker Creek: This population was first documented in the early 2000s, likely the result of natural migration from more robust herds, aided by suitable corridors and in some cases, additional augmentation.
As of 2024-2025, Arizona is home to approximately 1,300 Rocky Mountain Bighorn Sheep, a number that is both a testament to reintroduction success and a reminder of their still-vulnerable status compared to historic abundance.
For context, Arizona’s total bighorn sheep population—inclusive of both Rocky Mountain and Desert Bighorn subspecies—stands at about 6,000 animals, with roughly 5,600 being Desert Bighorn Sheep.
Year | Statewide Rocky Mountain Bighorn Sheep Estimate | Notes |
|---|---|---|
2015 | 1,200 | Range expansions in Eagle Creek, small translocations ongoing |
2021 | 1,250 | Stable, aided by ongoing Morenci/Eagle Creek population growth |
2023 | 1,300 | Recent translocation to Utah; population robust due to mine displacement management |
2024 | 1,300 | Confirmed in WAFWA and AZGFD annual reports |
Population figures are derived from helicopter-based surveys, ground counts, hunter check-ins, and telemetry data, with estimates adjusted for sighting probabilities and demography. Surveys are typically conducted every one to three years in core management units.
Arizona manages a very limited, highly regulated bighorn sheep hunt—only 15–25 Rocky Mountain Bighorn Sheep tags are issued annually statewide, representing less than 2% of the population and aimed strictly at Class III or IV (older) rams. Hunt success rates are high (90–95%), and the data gathered at hunter check-in stations contributes to population and health monitoring.
One of Arizona’s most notable contributions to bighorn sheep conservation in western North America has been its role as a source of Rocky Mountain Bighorn Sheep for transplants to other states. With the Eagle Creek–Morenci herds achieving sustainable numbers and at times exceeding local carrying capacity or presenting management challenges near urban areas, AZGFD has periodically captured and translocated sheep to support restoration projects in Utah, Colorado, New Mexico, Texas, and elsewhere.
Arizona’s interstate bighorn sheep transfers have a strong record of cooperation with neighboring wildlife agencies, especially with Utah Division of Wildlife Resources and the Wild Sheep Foundation. All translocated animals are screened for disease and typically represent a mix of ages and both sexes, emphasizing genetic diversity and rapid establishment of founder herds.
Year | Source Herd (Arizona) | Destination | Outcome |
|---|---|---|---|
2020 | Morenci/Eagle Creek | Antelope Island, UT | Establishment and supplementation of nursery herd following pneumonia die-off in Utah. Antelope Island designated as source for further Utah-wide restoration. |
2023 | Morenci (urban fringes) | Antelope Island, UT | 27 sheep captured/relocated via helicopter and ground teams; population on Antelope Island now near 80, expected to serve as future source for Utah reintroductions. Declared successful with low post-release mortality; all sheep tested and cleared for disease. |
Various (1980s–2010s) | Eagle Creek & others | Colorado, NM, TX, UT | Arizona sheep utilized for augmenting depleted or extirpated herds (dates and details vary; specific documentation available for Utah, with Antelope Island being the flagship project) |
Each of these events involved multi-agency and non-profit collaboration, including AZGFD, Utah DWR, Wild Sheep Foundation (both national and Utah chapters), KUIU Conservation Direct, and Sportsmen for Fish and Wildlife.
Colorado, New Mexico, Texas: Historic records and management plans indicate that Arizona sheep have supplemented existing herds and initiated new populations, although specific details and outcomes are more scant in recent years than for Utah events
