Unit 4, Colorado

Elevations range from approximately 6,300 feet in the sage-covered valley floors to just under 11,000 feet in the forested Elkhead Mountains along the unit's eastern boundary (all Elkhead peaks are sub-11,000 ft; no Continental Divide terrain exists within this unit). The western and northern portions feature rolling to gently broken terrain — open sage hills, dry creek drainages, and ranch country — transitioning east into steeper, timbered slopes and ridges within the Routt National Forest. The unit totals approximately 467 square miles (roughly 299,150 acres).

Primary paved access: US Highway 40 forms the southern boundary (Craig to Hayden); Colorado 13/789 forms the western boundary (Craig north to Wyoming). Interior access routes include Moffat County Road 1 and Routt County Road 82 (eastern boundary), and USFS Road 150 (along the Routt NF edge near the Elkhead Mountains). The Routt National Forest portion — managed by the Hahns Peak/Bears Ears Ranger District (office: Steamboat Springs, 970-870-2299) — is the main block of contiguous public land; most USFS roads are seasonal (approximately June 15–December 1). BLM lands (~32,000 acres) are managed by the Little Snake Field Office in Craig (970-826-5000) and are scattered through the western and central portions of the unit. State Wildlife Areas provide additional access. Approximately 53% of the unit is private ranch and agricultural land; checkerboard private ownership is common west of USFS 150, so hunters should verify land status before leaving roads. No designated Wilderness exists within GMU 4; the nearest is Mount Zirkel Wilderness to the east in adjacent GMU 14/5. Seasonal motorized closures apply on Routt NF USFS roads per the Motor Vehicle Use Map (MVUM).

Vegetation is dominated by shrub and scrub (approximately 45% of cover), including big sagebrush on the lower benches and basin floors and mountain shrub (oakbrush, serviceberry, bitterbrush) on mid-elevation slopes. Deciduous forest — predominantly aspen — accounts for roughly 29% of the unit, concentrated on the eastern forested ridges. Evergreen forest (spruce-fir and some lodgepole pine) makes up about 14%, mainly at higher elevations in the Routt NF portion. Riparian corridors line Elkhead Creek and smaller drainages throughout the unit. Low-elevation areas near Craig and along US 40 carry dry grassland and juniper components.

Elk are widespread; summer range concentrates in the Routt NF aspen and spruce-fir at higher elevations, with bulls often rutting in the upper sage and aspen edges beginning in early September. As snow pushes herds lower in October and November, animals filter into lower aspen draws, oakbrush, and private ranch lands along US 40 and CO 13. Mule deer follow similar seasonal patterns — high-country summer range descending to sage and oakbrush winter range in the western and southern portions. Pronghorn occupy the open sage flats and grass benches in the central and western portions year-round, with the largest concentrations on private and BLM lands. Black bear are present throughout the forested eastern portion during spring green-up and berry season. Mountain lion range the unit following deer concentrations. Moose have been documented in riparian willow and alder habitat along Elkhead Creek and other drainages. Turkey are present in the oak and riparian zones.

1. Elk harvest (2022): 1,362 total, 4,724 hunters, 29% success — confirmed from CPW 2022 Elk Harvest PDF. Archery-only: 102 elk, 25% success, 404 hunters. Muzzleloader-only: 32 elk, 16% success, 202 hunters. 2. Deer harvest (2024): 384 total, 678 hunters, 57% success — confirmed from CPW 2024 Deer Harvest PDF. 3. Public land percentage (47%: USFS 30%, BLM 11%, State 6%) confirmed via HuntScore unit profile. 4. Pronghorn harvest statistics not available in reviewed public sources; contact CPW or consult the Draw Recap Report. 5. Moose presence documented in secondary sources (riparian willows near Elkhead Creek) but no designated moose hunt code for GMU 4 found; not included in species_data. 6. Mountain Lion: draw tag, no unit-specific season data found in public sources; not included in species_data. 7. The 1st season elk rifle (Oct. 14–18) for Unit 4 is grouped with units 3, 5, 301, and 441 under hunt code E-E-003-O1-R (either-sex) — a 2026 regulatory change confirmed by onX and CPW 5-year season structure document. 8. HuntScore incorrectly references '12,000 ft along the Continental Divide' for this unit; the Elkhead Mountains are all sub-11,000 ft and the Continental Divide does not run through GMU 4. 9. No wilderness areas exist within GMU 4 boundaries.