Unit 10, Colorado

Elevation ranges from approximately 5,100 feet at the White River lowlands to Blue Mountain mesa (exact elevation not confirmed in primary sources) and Moosehead Mountain at 7,838 ft. Diamond Mountain is referenced in secondary sources as the unit's highest point but its precise elevation is disputed — PeakVisor lists a Moffat County Diamond Mountain at 8,543 ft, not the 9,700 ft figure sometimes cited. The landscape is characterized by rolling desert hills, rock outcroppings, mesa rims, and deeply incised river drainages carved by the Green, Yampa, and White rivers. Terrain is rugged in the northern reaches near Dinosaur National Monument; softer sage-covered hills and benches dominate the center and south. Four-wheel-drive is typically required to reach interior BLM tracts.

The unit is primarily managed by the BLM White River Field Office (220 E. Market St., Meeker, CO; 970-878-3800) and the BLM Little Snake Field Office (Craig, CO; 970-826-5000). Primary highway access: US Highway 40 on the eastern edge; US Highway 64 along the southern boundary (Rangely corridor). Harper's Corner Road (off US Hwy 40) provides northern access toward Dinosaur NM and to Moosehead Mountain state trust land (640 acres, GMU 10, Moffat County; open Aug 15–end of February for hunting; foot and horseback access only via BLM land along Harper's Corner Road and Moffat County Road 16; valid hunting license required for all ages 16+). County Road 14 accesses cedar-covered BLM in the Hank Mountain area. Many interior BLM roads are two-track dirt requiring 4WD. Dinosaur National Monument occupies the unit's northwestern corner and is CLOSED to all hunting — wildlife attractants (elk bugles, calls) are also prohibited along the Harper's Corner Road right-of-way; hunters may possess legal firearms while transiting on monument roads, and may transport lawfully taken game through the monument. The Diamond Breaks Wilderness Study Area prohibits motorized vehicles including OHVs. Approximately 22% of the unit is private land in a checkerboard pattern; careful map consultation is required.

Lower elevations (below ~6,500 ft) are dominated by sagebrush and sage-grassland with Indian grass, greasewood, and buckbrush. Mid-elevations support pinyon-juniper woodland intermixed with mountain shrub — oakbrush, serviceberry, and bitterbrush. Riparian corridors along the White River, Yampa River, and Green River support willow and cottonwood galleries. Diamond Mountain and Blue Mountain mesa tops carry denser mountain shrub and scattered conifers. There is no significant aspen or spruce-fir zone within the unit.

Elk are the primary trophy species; the unit falls within the E-21 Rangely/Blue Mountain elk herd (DAU). Large bulls in the 300-inch-plus class are documented regularly. Elk tend to be resident year-round rather than undertaking dramatic migrations; movement is weather-driven, with bulls concentrated around Blue Mountain, Moosehead Mountain, and the Hank Mountain basins. Some elk move from Dinosaur National Monument into the unit during dry years seeking better forage. Mule deer are scattered throughout the unit; bucks tend toward tall-framed antlers. Deer shift to lower elevations during third-season rifle hunting as winter weather triggers movement. Pronghorn are present on the sage flats, primarily in the southern and central portions. Black bear inhabit brushy mid-elevation oakbrush and mountain-shrub transition bands. Mountain lion are present. Wild turkey (Rio Grande subspecies) exist in lower numbers along river drainages. Sage grouse and dusky (blue) grouse are present. Moose have been documented in riparian corridors in the broader region.

1. Tag quota of 32 for early either-sex elk rifle draw confirmed by cohunter.com article citing wildlife manager Bill de Vergie; verify in current CPW draw recap as quotas change annually. 2. Preference points: 22 resident / 27 nonresident confirmed from cohunter.com (approximate — treat as reference, not guarantee). 3. Browns Park NWR is confirmed to be within GMUs 1 and 201 per the official FWS hunting brochure — it is NOT in GMU 10; the draft's reference to it in GMU 10 has been removed. 4. Diamond Mountain elevation: 9,700 ft figure from earlier draft is not confirmed; PeakVisor lists a Moffat County Diamond Mountain at 8,543 ft — elevation claim softened pending primary verification. 5. NPS archery/bow permit requirement at Dinosaur NM: unverified in any NPS primary source — removed. 6. Season dates use the official CPW 2025–2029 Big Game Season Structure document; 2026 dates verified. 7. E-21 Rangely/Blue Mountain herd management plan is under revision as of 2023–2024 public meetings; population objective of ~1,200 and estimate of ~1,480 from 2020–21 CPW guide are not confirmed in current primary sources and have been removed from the profile body pending updated HMP publication.