Colorado GMU 231 Pronghorn Hunting
Routt, Rio Blanco and Garfield counties, northwest Colorado · 178 sq mi
Based on the EASIEST unit-wide buck or either-sex hunt code available to adult Colorado residents in the 2026 primary draw — the lowest preference-point tier that drew reliably. Private-land-only and Ranching for Wildlife hunts are excluded because neither is a unit-wide public-land opportunity — NOT because the public cannot draw them. A private-land-only license requires the hunter's own permission to hunt private ground; a Ranching for Wildlife license is valid on the participating ranches enrolled in that program. They are separate systems. Other weapons, seasons and nonresident applicants can require substantially more points. The band is a floor, not a target: even the easiest qualifying hunt here sits in that range.
What hunting GMU 231 is like
Unit 231 spans 178 square miles across Routt, Rio Blanco and Garfield counties in the unit's northwestern region, encompassing terrain that rolls from low elevations near 6,900 feet through typical country around 8,900 feet to high ground above 12,100 feet. The landscape is rolling, with some steeper breaks: 52% of the unit is gentle terrain, 41% moderate, and 7% steep or rugged. This mix of slopes and elevations creates a range of hunting country from open benchland to timbered drainages.
National Forest and BLM lands make up roughly 63% of the unit and are generally open to public hunting, providing a reliable base of accessible ground. State Trust Land comprises about 1.1% of the unit, though only parcels enrolled in CPW's Public Access Program may be hunted. Private land accounts for roughly 36% of the unit, which can create access challenges in some areas where public and private ground interweave.
Pronghorn range across 24% of the unit according to CPW's Overall Range mapping. Because that layer represents the full extent of mapped range rather than year-round occupancy, it does not indicate where pronghorn concentrate through the fall or how distribution shifts as the season advances. Hunters should expect to locate pronghorn through scouting and local knowledge rather than assuming consistent presence across the mapped range.
Unit 231 offers three pronghorn seasons: a muzzleloader season from September 21 to September 29 for either-sex hunting, a rifle season from October 3 to October 11 also for either-sex, and a private-land-only season from September 26 to October 18 for does. September highs average 64°F, cooling to October highs around 52°F and further declining into November. October brings an average of 4.9 inches of snowfall and November nearly 19 inches, creating conditions that shift rapidly as the fall progresses. The draw for this unit is easy, with the most accessible either-sex buck or doe seasons often drawing at zero preference points.
Terrain & elevation
- Elevation
- 6,900–12,100 ft, typically around 8,900 ft
- Steepness
- Moderate — mean slope 11.3°
- Slope breakdown
- 52% gentle · 41% moderate · 6% steep · 1% rugged
- Ground you can count on
- ~112 sq mi, plus ~2 sq mi of State Trust Land where access depends on enrollment
Habitat & cover
What actually grows here, by elevation. Each band adds to 100% on its own — these are shares of that band, not of GMU 231.
Lower elevations
- Aspen41%
- Sagebrush41%
- Other cover10%
- Conifer5%
- Riparian4%
Mid elevations
- Aspen50%
- Conifer38%
- Sagebrush8%
- Other cover2%
- Riparian1%
Higher elevations
- Conifer53%
- Sagebrush28%
- Aspen8%
- Riparian6%
- Grass and meadow4%
- Other cover1%
Cover classes from the USGS National Land Cover Database, split into elevation bands. “Other cover” is the remainder of the classification — bare ground, water, agriculture and developed land — and is left unnamed rather than guessed at.
Land & access
About 63% of GMU 231 is public land a hunter can count on — National Forest and BLM. A further 1% is State Trust Land, which is huntable only where CPW has enrolled it.
- National Forest61%
- BLM2%
- State Trust Land1%
- Private36%
Colorado State Trust Land is open to public hunting only where it is enrolled in CPW's Public Access Program. Check current enrollment before planning around it.
Where pronghorn live in the unit
Colorado Parks & Wildlife maps pronghorn seasonal ranges statewide. This is how much of GMU 231 each range covers — the single best clue to whether pronghorn are here in September, in November, or only passing through. The layers overlap, so they do not add to 100%.
- Overall Range24%the full extent of range CPW maps for pronghorn — near 100% on most units, and not a statement about when pronghorn are present
Pronghorn seasons & weapons (2026)
| Season | Dates | Tags offered |
|---|---|---|
| Muzzleloader | September 21 – September 29 | Doe, Buck |
| Rifle | October 3 – October 11 | Doe, Buck |
| Private-land only | September 26 – October 18 | Doe |
Dates span every hunt code of that type in this unit and can differ by code. Confirm the current brochure with Colorado Parks & Wildlife before applying.
Fall weather
- September — highs around 64°F, lows around 38°F, about 0.1 in of snow (mid-elevation normals)
- October — highs around 52°F, lows around 28°F, about 4.9 in of snow (mid-elevation normals)
- November — highs around 39°F, lows around 17°F, about 19.4 in of snow (mid-elevation normals)
GMU 231 pronghorn hunting FAQ
Can someone with zero preference points draw pronghorn here?
Yes. The easiest unit-wide buck or either-sex seasons draw reliably at zero preference points in the primary draw. That scope covers the most accessible hunts; other seasons and weapons may require more points. Hunters can also pursue over-the-counter archery tags where available, enter the secondary draw in June, or check the leftover list after the primary draw closes.
Is this unit realistic for a public-land hunter with limited ground access?
About 63% of the unit is National Forest and BLM land open to public hunting, offering a substantial base for scouting and hunting. However, public and private land is interspersed across the unit, so access to any specific location depends on ground-truth checking and may require route-planning to reach some areas. State Trust Land parcels enrolled in CPW's Public Access Program add to available ground where they exist.
Is this better as an early-season or late-season hunt?
The muzzleloader season (September 21–29) occurs during the primary rut phase, when pronghorn are actively pursuing does and may be more responsive to calling. The rifle season (October 3–11) falls in the late-rut and post-rut recovery phase, after peak breeding activity has declined. Early season offers rut-phase hunting, while late season arrives as animals transition toward fall grouping behavior.
How much does terrain difficulty affect hunting here?
The rolling terrain with some steeper breaks allows hunters to cover ground and locate pronghorn across varied country without requiring extensive scrambling. At 52% gentle and 41% moderate slopes, a hunter on foot can access most of the unit's hunting country. The 7% steep or rugged terrain provides more-difficult pockets but does not dominate the landscape.
What should a hunter expect from weather and snow as the season progresses?
September opens mild with highs around 64°F and minimal snow, but the fall cools rapidly. October brings highs near 52°F and an average of 4.9 inches of snowfall, while November drops to highs around 39°F with heavy snow averaging 19.4 inches. Hunting conditions shift significantly from early September into November, and late-season hunters should prepare for deep snow and cold.
How does the draw difficulty here compare to the effort required?
The unit draws as easy, often at zero points, reflecting low overall hunter pressure. This accessibility means applicants can pursue pronghorn here without accumulating preference points, though this ease-of-draw does not account for on-the-ground hunting difficulty or physical demands once in the field.
Data sources & methodology
- Colorado Parks & Wildlife — Big Game hunting — seasons, weapons, hunt codes and license types
- CPW — Primary Draw rules — how preference points and the hybrid draw work
- CPW — Pronghorn statistics, draw recap and Drawn Out At reports — the point levels behind the draw-difficulty bands
- CPW — Secondary Draw — licenses remaining after the primary draw
- USGS / MRLC — National Land Cover Database — habitat and cover classes by elevation band
- CPW — Maps and GIS (Species Activity Mapping) — pronghorn seasonal range
- CPW — State Trust Land Finder — which State Trust acreage is enrolled and open to public hunting
- USGS PAD-US — Protected Areas Database of the United States — land ownership and access
- Daymet daily climate, 1991–2020 (Oak Ridge National Laboratory) — fall weather
Draw difficulty is a qualitative band, not published odds — the note under the summary above states exactly which hunt code it describes. Land shares are separate, non-overlapping categories: publicly owned is not the same as open to hunting, and State Trust Land is huntable only where CPW has enrolled it. Unit data last updated September 24, 2026.