How big is GMU 139 in Colorado?

GMU 139 (GMU 139 — Baca Co.) covers about 1,203 square miles, ranging from roughly 3,900 to 4,900 feet in elevation. Area is computed from the unit boundary polygon.

What species does the catalog list for GMU 139?

Mule Deer, Pronghorn, Whitetail Deer, Rocky Mountain Elk. For seasons, tags, and regulations, use the official Colorado agency resources linked on this page — this page carries no regulatory information.

GMU 139 GMU 139 — Baca Co.

The strongest deer and pronghorn of the far southeast, with real public ground in the Carrizo canyon country

Southeast Colorado — Baca County plains and Comanche Grassland canyons · Last reviewed 2026-07-12

Mule deer buck trotting across open prairie at dusk

Area

1,203

sq mi

Public land

15%

approx.

Elevation

3,900–4,900

feet

Motorized

moderate

access

Overview

GMU 139 is a large unit covering eastern and southern Baca County in Colorado's far southeast corner, where the shortgrass plains give way to the piñon-juniper canyons of the Carrizo Unit of the Comanche National Grassland. That mix is what makes it the standout of the far-southeast units: mule deer are the top harvest and hold strong numbers in the canyon breaks and piñon country, pronghorn work the open flats, and elk are only an incidental presence. Crucially, the Comanche National Grassland gives this unit genuine public land — real walk-in canyon country — where its plains neighbors have almost none.

Terrain

Open shortgrass and sandsage flats broken by rugged piñon-juniper canyons and rocky rims — Carrizo, Cottonwood and Picture Canyon country — draining toward the Cimarron River in the southeast corner.

Cover: Shortgrass prairie, sandsage and yucca on the flats; piñon-juniper woodland and scrub oak on the canyon slopes and rims; cottonwood and brushy bottoms along the drainages and the Cimarron River.

Landmarks: Comanche National Grassland (Carrizo Unit) · Carrizo Canyon · Cottonwood Canyon · Picture Canyon · Cimarron River · Springfield / Walsh vicinity

Access

Much of the unit is private ranch and dryland farm ground, but the Carrizo Unit of the Comanche National Grassland provides substantial USFS public land in the canyon country — genuine walk-in hunting for mule deer and, on the fringes, pronghorn. Colorado State Trust Lands are generally NOT open to hunting unless enrolled in CPW's Public Access Program, so do not treat them as huntable. Plan around the grassland public parcels, then layer in landowner permission or landowner tags for the surrounding private flats and canyon rims.

Managers: USFS Comanche National Grassland (Carrizo Unit), private ranch, private farm, Colorado State Trust Land (mostly closed)

Access points: Comanche National Grassland / Carrizo Unit access roads (Carrizo, Cottonwood, Picture Canyon) · County Road M and grassland roads south of Springfield and Walsh · U.S. Highway 160 and 287 corridors · landowner-permission access on adjacent private ranches

Species notes

Mule Deer

common quality

The top harvest species — mule deer hold in good numbers in the piñon-juniper canyons, rocky breaks and brushy draws of the Carrizo country, with strong success for a plains unit. Fully limited-draw, and the canyon habitat can grow mature bucks.

→Glass canyon rims and piñon-juniper pockets at first and last light
→Still-hunt the mesa breaks and scrub-oak draws mid-day
→Hunt the Comanche National Grassland canyon access hard for undisturbed bucks
→Work the Cimarron and Cottonwood drainage bottoms where deer feed and water

Pronghorn

common opportunity

A strong secondary draw — pronghorn range the open shortgrass and dryland flats between the canyons, with solid success. Limited-draw; access on the private flats is the main constraint.

→Drive-and-glass the open flats and grassland edges at first light
→Use rolling terrain and sandsage for a careful stalk once a buck is located
→Hunt water tanks and stock ponds in dry early seasons
→Combine grassland public ground with landowner permission on the private flats

Whitetail Deer

limited opportunity

A limited whitetail presence along the cottonwood bottoms of the Cimarron River and the wetter canyon drainages in this far-southeast corner — secondary to the dominant mule deer. Fully limited-draw.

→Hunt cottonwood river bottoms and brushy riparian edges at dawn and dusk
→Watch trails between bedding cover and cropland or grassland feed
→Focus on the Cimarron corridor and canyon-bottom thickets

Rocky Mountain Elk

limited low

Only an incidental, low-density plains elk presence — recent harvest is a couple of animals. Not a species to plan a hunt around here. Limited-draw only (no OTC).

→Glass the roughest, quietest canyon country and largest private tracts where a stray herd might shelter
→Treat any elk as a bonus while hunting deer or pronghorn
→Check the grassland canyon heads for the occasional resident bunch

Pro tips

→Anchor your plan on the Comanche National Grassland (Carrizo Unit) — it is the real public ground that sets this unit apart from its neighbors
→The canyon piñon-juniper country is the mule-deer engine; the open flats are the pronghorn engine — hunt them differently
→Confirm State Trust Land parcels are enrolled in Public Access before hunting them; most are closed
→Glass canyon rims at first light before deer drop into shaded cover
→Check the Cimarron cottonwoods for the occasional whitetail
→Water sources rule early-season movement in dry years

Watch out for

!Large private ranches gate much of the flats and canyon rims — get permission or a landowner tag
!State Trust Land is generally closed to hunting unless in CPW's Public Access Program
!Rough grassland canyon roads become impassable when wet; carry recovery gear
!Steep rims and loose rock — plan retrieval before shooting deep in a canyon
!Grass and piñon-juniper fire risk in dry, windy conditions

Logistics

Base from Springfield (the Baca County seat) or Walsh for lodging, fuel and services, with Lamar to the northwest as a larger hub. Grassland canyon roads are rough gravel and dirt — high clearance helps, and 4WD is smart in wet weather. Cell service is spotty away from the highways. Scout the Comanche National Grassland boundaries and pin the State Trust parcels you must avoid before you hunt.

Nearest towns: Springfield, Walsh, Campo, Lamar, Pritchett

Nearby units

GMU 145 · GMU 145 — Baca Co. GMU 138 · GMU 138 — Baca Co. GMU 132 · GMU 132 — Prowers Co. GMU 144 · GMU 144 — Baca Co.

Seasons & regulations

This page carries no season dates or regulations. Get current rules from the official Colorado sources:

Research sources: CPW Game Management Units (GMU) boundaries — Colorado Geodata · HuntScore — GMU 139 Deer (Baca County) · Monster Muleys — Mule Deer Hunts in Units 135, 139, 144 and 145 · Comanche National Grassland — Wikipedia

FAQ

How big is GMU 139 in Colorado?: GMU 139 (GMU 139 — Baca Co.) covers about 1,203 square miles, ranging from roughly 3,900 to 4,900 feet in elevation. Area is computed from the unit boundary polygon.
How much public land is in GMU 139?: Approximately 15% of the unit is public land. Primary managers: USFS Comanche National Grassland (Carrizo Unit), private ranch, private farm, Colorado State Trust Land (mostly closed). Always verify ownership boundaries on the ground.
What species does the catalog list for GMU 139?: Mule Deer, Pronghorn, Whitetail Deer, Rocky Mountain Elk. For seasons, tags, and regulations, use the official Colorado agency resources linked on this page — this page carries no regulatory information.

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