The Lolo & Bitterroot National Forests

ELK – SAPPHIRE HERDS

Elk that calve and summer in the Sapphire Mountains migrate west to winter on the grassland/sagebrush slopes on the eastern benches of the Bitterroot Valley throughout Hunting Districts 204, 216, 261, and the northern portions of 240, which is located on the western side of the valley. This stretch of winter range runs along U.S. Route 93 between the communities of Lolo to the north and Darby to the south. The largest number of elk generally winter on the east side of the highway but will cross the roadway to utilize habitat on the west side as well. Larger wintering populations tend to congregate around Davis Creek, Eight-Mile (MPG Ranch), Burnt Fork, and Lower Willow Creek. These winter ranges include both public lands within the Lolo National Forest and adjacent state lands and private ranches. Threats to these migration routes and winter ranges include invasive plants, conifer encroachment, roadway barriers, vehicle collisions, and the fragmentation and development habitat. Residential development and associated winter range fragmentation are of particular concern on the foothills and valleys east of the communities of Florence, Stevensville, and Hamilton along the base of the Sapphire Mountains.

ELK – EAST FORK HERDS

The East and West Forks of the Bitterroot River are the headwaters for the main stem of the Bitterroot River and provide excellent big game habitat. The East Fork herd has historically higher populations. The East Fork tends to hold less snow, more open winter ranges, and more productive grass and shrub communities than the West Fork. Surveys conducted in 2021 counted 4,052 elk in HD 270, which has one of the largest elk populations in western Montana. Approximately 2,000 elk winter on the CB Ranch and French Basin areas. During the 2020 general rifle season, the FWP check station at Darby documented more than 4,000 hunter trips—2,500 of which were to HD 270. Many elk in the East Fork migrate up through the headwaters and over the Continental Divide to the high-elevation summer ranges of the Anaconda-Pintler Range in the Big Hole River watershed, an area managed by the neighboring Beaverhead Deerlodge National Forest. Many of the elk that summer north of Highway 43, north and west of Wisdom (HD 321), will migrate back into the East Fork to winter. Threats to these big game populations, migration routes, and winter ranges include predation, invasive plants, conifer encroachment, degraded grasslands, and the fragmentation and development of private lands.

ELK – WEST FORK HERDS

Elk habitat in the steeper, wetter, and more heavily timbered West Fork of the Bitterroot watershed falls within HD 250. In 2021, surveys counted 806 elk in this area, fewer than one-quarter of the number of animals found that year in the East Fork. As with the Sapphire elk herds, these elk summer in higher elevations of the Bitterroot National Forest and then migrate down to the open slopes near the valley bottom, primarily on private ranches. Threats to these big game populations, migration routes, and winter ranges include invasive plants, conifer encroachment, degraded grasslands, predation, and the fragmentation and development of private lands. Between 2005 and 2009, elk surveys showed severe declines in elk numbers and recruitment, primarily in the West Fork of the Bitterroot in HD 250. An ensuing study completed in 2014 showed that suboptimal habitat and predation (primarily by mountain lions) had contributed significantly to reduced adult elk survival and calf recruitment.

MULE DEER

The Bitterroot National Forest provides extensive habitat for mule deer in western Montana. Populations remain stable in some areas of the forest while trending down in other areas. Total population estimates in FWP Region 2 have shown a decline of 27 percent over the past ten years. Hunting Districts 204, 250, 262, 261, 270, and the southern portions of 240 are all popular mule deer hunting districts. Mule deer hunting permits in HD 270 are the most highly coveted antlered buck permits in the state of Montana. Last year, 8,500 hunters applied for 45 available permits. HDs 262 and 261 also offer highly coveted hunts. During the summer months, mule deer generally inhabit the higher-elevation timbered lands in the Sapphires, moving down in the winter to lower-elevation grasslands on Three Mile and Calf Creek Wildlife Management Areas, as well as other winter ranges on private land around the Burnt Fork of the Bitterroot River and Dry Creek. Private lands on and around the MPG Ranch in HD 204 also provide important winter range. In some instances, smaller populations of mule deer may remain year-round in the same general locations, including in HD 262. Threats to Bitterroot NF mule deer migration routes and winter ranges include invasive plants, conifer encroachment resulting in poor forage conditions, and the fragmentation and development of winter ranges.

BIGHORN SHEEP

The Bitterroot National Forest provides habitat for both stable and recovering bighorn sheep populations. Stable populations of bighorn sheep occur in locations such as Skalkaho Pass (HD 261), Painted Rocks (HD 250), and the East Fork of the Bitterroot (HD 270). The Skalkaho herd numbers about 80 animals. This unit provides sheep habitat on the state-owned Calf Creek WMA and has a high percentage of private land (>50%). The Painted Rocks/Watchtower herds utilize winter ranges in the Selway River drainage and the Painted Rocks Reservoir. These sub herds total about 120 animals. While the movements of bighorn sheep across the landscape are typically not as extensive as those of elk or mule deer, herds in the Bitterroot utilize migration routes and seasonal ranges to complete their lifecycles. The largest and most mobile of these three herds is the East Fork herd, which numbers around 200 animals. In 2019, a collared ram in the East Fork moved 15 miles into the higher-elevation habitats near the divide before returning to its traditional ranges. Important winter ranges for this herd include the southwest facing slopes of Sula Peak, Robbins Gulch, and Spring Gulch. While many of the ewes and young rams remain in these areas for the summer, many of the mature rams move to habitats near Fish Lake, Hope Lake, and Charity Lake. Threats to bighorn sheep and their habitats include successional changes in vegetation, human development and disturbance, predation in lambing areas, vehicle collisions, disease transmission from domestic livestock, and genetic bottlenecks.