Unit 4, New Mexico

GMU 4 spans roughly 694 square miles (approximately 444,000 acres) with an elevation range of approximately 6,837 to 10,915 feet. River-bottom valleys along the San Juan, Animas, Los Pinos, and Rio Chama drainages sit at the lower end, rising through rolling sagebrush plains and pinyon-juniper foothills to the heavily forested Brazos Mountains, whose high point (Grouse Mesa) reaches 11,405 feet with Brazos Peak at 11,288 feet. U.S. Route 64 crosses the southern Brazos at a 10,481-foot pass — the highest paved through-road pass in New Mexico (confirmed via Wikipedia/Brazos Mountains). The eastern reaches include the Brazos Cliffs escarpment. The western and central portions of the unit are characterized by exposed dirt, rock, gravel, and sandy desert foothills with active oil-field infrastructure. Public-land terrain in the WMAs is notably steep. Rattlesnake Canyon, located within the unit, is closed to hunting.

Public land constitutes approximately 13% of the unit (HuntScore; GoHunt estimates 11.7% — 13% used as the more conservative figure), with approximately 87% in private ownership. BLM land within the unit is minimal (~3,840 acres) and state trust land totals roughly 63,000 acres. There is no Carson National Forest land within GMU 4 boundaries, though Carson NF (Coyote and Tres Piedras Ranger Districts) adjoins the unit to the east and south. The three public-access WMAs where draw tags are issued for public hunters are: (1) Edward Sargent WMA (~20,400 acres) — just north of Chama reaching the Colorado state line, accessed from US-64/US-84 in Chama, no motorized vehicles inside; (2) Bill Humphries WMA (~10,950 acres) — approximately 10 miles west of Chama off US-64, straddles the Continental Divide; (3) Rio Chama WMA — approximately 14 miles south of Chama, bordering El Vado Lake State Park. WMA draw tags are restricted to New Mexico residents only. State trust land accessible via public roads is open to licensed hunters (14-day pre-season scouting; no off-road vehicles). Primary highway access is via US-64/US-84 through Chama; NM-112 runs north toward Colorado. The Jicarilla Apache Indian Reservation forms the western boundary and is closed to non-tribal hunting without a separate Jicarilla permit. EPLUS landowner authorizations in this unit are tied to enrolled ranch properties; a tag may be used on any private land in the unit with written landowner permission, but no unit-wide OTC-style authorization exists.

Land cover is roughly 33% shrub/scrub, 26% evergreen forest, 20% grassland/herbaceous, and 10% deciduous forest based on NLCD-class estimates. Low elevations support sagebrush, mixed grassland, and cropland/hay fields (especially alfalfa) along major river bottoms. Mid-elevations carry pinyon-juniper with oak brush. Upper slopes in the Brazos Mountains and the Sargent and Humphries WMAs transition to ponderosa pine, then mixed conifer (Douglas fir, white fir, Engelmann spruce) with aspen parks and alder-lined streams. River bottoms contain cottonwood, tamarisk, and willow with some marshy areas. The Continental Divide runs through the western portion of the unit (Bill Humphries WMA straddles the Divide in the Chama vicinity).

Elk are the unit's signature species; GMU 4 is part of New Mexico's North-Central Herd Unit, which holds the state's largest elk population (confirmed by NMDGF 2023-2024 Elk Hunting Forecast). Migratory bulls from Colorado move into the unit as November snows deepen, concentrating on lower-elevation ranches along migration corridors. The rut typically begins in early September. Mule deer are abundant and Rio Arriba County ranks among the top Boone and Crockett counties in North America — 24 typical entries and 9 of the top 10 NM mule deer recorded by B&C originated here. Deer from Colorado also migrate south into the unit as winter approaches. Pronghorn antelope occupy the lower sagebrush and grassland flats. Black bear range throughout the forested WMA areas and higher-elevation private ranches. Merriam's turkey inhabit the mixed-conifer and ponderosa zones on the WMAs and adjacent private lands. Mountain lion are present as resident predators. The oil-field and river-bottom country on the western side near the reservation boundary holds mule deer year-round.