Unit 51B, New Mexico

GMU 51B is characterized by gently rolling mountains and mesas with the most dramatic relief where ridges drop into river and creek drainages; the western boundary follows the Rio Chama, where sandstone and siltstone canyon walls rise up to 900 feet above the river (confirmed by BLM). Elevations range from approximately 6,200 feet on lower canyon floors to about 8,100 feet on higher mesa tops, though the BLM and Hunt Talk sources cite the broader Unit 51 range from roughly 5,800 to 7,200 feet. The southern portion of the unit holds more timber and steeper, more broken terrain, while the northern and central sections trend toward open mesa and rolling sagebrush grasslands.

US Highway 84 forms the eastern boundary of 51B (separating it from 51A). NM Highway 112 branches west from US 84 near Tierra Amarilla to reach El Vado Ranch and the upper Rio Chama put-in. NM 221 and County Road 303 from US 84 provide access to the Rio Chama WSA. Forest Road 151, a dirt road north of Ghost Ranch on US 84, provides access to the lower Rio Chama corridor and enters the unit but is impassable when wet. The Chama River Canyon Wilderness (Carson National Forest, Tres Piedras/Abiquiu Ranger District) and the Rio Chama Wilderness Study Area (BLM, Taos Field Office, 575-758-8851) occupy a large portion of the public land; foot and horseback travel is required inside designated wilderness. About 66.3% of the unit is public land (Carson NF, BLM, and some New Mexico State Trust land); private ranches concentrate in the northeastern corner and create limited access barriers in that area. State Trust land parcels require a recreational access permit (NMSLO Hunting Access Program) to enter legally. The Rio Chama is designated a Wild and Scenic River (24.6 miles: 21.6 wild + 3.0 scenic, designated November 7, 1988); river-corridor access via raft or kayak is an alternative entry method. ATV use is permitted on designated roads within the unit (unlike the adjacent roadless Unit 52). Some EPLUS unit-wide ranch authorizations may exist in the northeast corner — verify current status on the NMDGF interactive EPLUS map before hunting.

Lower elevations and mesa slopes support pinyon pine and juniper woodland with wild grasses, Gambel oak, and mixed shrubs. Ponderosa pine appears in creek bottoms and on north-facing slopes beginning around 7,500 feet. The Rio Chama corridor is lined with riparian vegetation including cottonwood and willow in the canyon bottom; adjacent flats and benches carry sagebrush and grassland. North-facing canyon walls support denser mixed conifer pockets — including Douglas fir (confirmed present by BLM WSA page) — within an otherwise semi-arid pinyon-juniper matrix.

The unit holds good numbers of Rocky Mountain elk on public land; 51B is part of the Chama/San Antonio Herd Unit (GMUs 4, 5B, 50, 51, 52), estimated at 25,300–29,000 animals with a 38:100:35 bull:cow:calf ratio as of the 2024 season. Hunt Talk reports describe Unit 51 as a solid meat-hunter's unit with healthy elk numbers but few true trophy bulls; hunting pressure is moderate and increases with road access. Elk use the timber draws and ponderosa-fir transition zones for cover and move between mesa grasslands and canyon-bottom drainages seasonally. Mule deer numbers are low unit-wide relative to neighboring units. Black bear inhabit the timbered drainages and pinyon-juniper foothills (Bear Zone 1). Mountain lion are present throughout. Merriam's turkey occur in the ponderosa-pine zone along creek drainages. The Rio Chama and its tributaries support resident trout and occasional waterfowl in riparian areas. No pronghorn, bighorn sheep, oryx, javelina, or Barbary sheep are established in this unit.