Colorado GMU 131 Mule Deer Hunting
Routt and Rio Blanco counties, northwest Colorado · 193 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 131 is like
GMU 131 spans 193 square miles of rolling terrain with some steeper breaks across Routt and Rio Blanco counties in the northwestern corner of the state. Elevations range from 6,500 feet to 9,100 feet, with terrain split across 51% gentle slopes, 39% moderate slopes, and 10% steep terrain. The rolling character of the country, punctuated by ridges and drainages, makes this ground walkable for hunters willing to cover distance on foot.
Public access here is sharply limited. Generally open ground—BLM, State Wildlife Areas, and National Forest—comprises roughly 11% of the unit or about 21 square miles. An additional 5.5% is Colorado State Trust Land, huntable only where CPW has enrolled parcels in the Public Access Program; which parcels are enrolled is unknown. Private land claims 82% of the unit, leaving legal access as the binding constraint on where a hunter can actually hunt, regardless of terrain difficulty. About 1.6% of the unit ownership is unclassified.
Mule deer occupy Summer Range across the entire unit and Overall Range across 100% as well. Winter Range covers only 7% of the unit, with Winter Concentration confined to 1%. This pattern reflects the unit's overall moderate elevation and suggests mule deer are broadly distributed across the unit through the fall hunting seasons, rather than concentrated in tight winter grounds early in the year.
The unit offers five seasons for mule deer, four of which are open to the public. Archery runs September 2–30 and is either-sex. Muzzleloader runs September 12–20 and is doe or buck. Two rifle seasons follow: 2nd Rifle October 24–November 1 (buck only) and 3rd Rifle November 7–15 (buck only). A private-land-only season runs October 24–November 15. The archery and muzzleloader seasons fall in the velvet-shed and early fall transition period. The 2nd Rifle season spans the early fall migration and nocturnal buck phase into early pre-rut staging. The 3rd Rifle season coincides with early pre-rut staging and the primary rut. Temperatures cool from September highs near 71°F to November highs near 43°F; October averages about 2.1 inches of snowfall and November averages about 10 inches. The unit draws with easy difficulty, typically at zero preference points for the most accessible buck or either-sex opportunity.
Terrain & elevation
- Elevation
- 6,500–9,100 ft, typically around 7,300 ft
- Steepness
- Moderate — mean slope 12°
- Slope breakdown
- 51% gentle · 39% moderate · 10% steep · 0% rugged
- Ground you can count on
- ~21 sq mi, plus ~11 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 131.
Lower elevations
- Sagebrush62%
- Other cover19%
- Aspen12%
- Riparian4%
- Grass and meadow2%
- Conifer1%
Mid elevations
- Aspen54%
- Sagebrush38%
- Other cover4%
- Conifer3%
- Grass and meadow2%
Higher elevations
- Aspen64%
- Sagebrush25%
- Conifer8%
- Other cover3%
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 11% of GMU 131 is public land a hunter can count on — BLM, State Wildlife Areas and National Forest. A further 5% is State Trust Land, which is huntable only where CPW has enrolled it.
- BLM9%
- State Wildlife Area1%
- National Forest<1%
- State Trust Land5%
- Unclassified ownership2%
- Private82%
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.
“Ownership unclassified” means the source dataset does not record an owner for that acreage. It is not known to be public or private.
Where mule deer live in the unit
Colorado Parks & Wildlife maps mule deer seasonal ranges statewide. This is how much of GMU 131 each range covers — the single best clue to whether mule deer are here in September, in November, or only passing through. The layers overlap, so they do not add to 100%.
- Summer Range100%used in summer
- Overall Range100%the full extent of range CPW maps for mule deer — near 100% on most units, and not a statement about when mule deer are present
- Winter Range7%used in winter
- Winter Concentration<1%where mule deer bunch up in winter
Mule Deer seasons & weapons (2026)
| Season | Dates | Tags offered |
|---|---|---|
| Archery | September 2 – September 30 | Either-sex |
| Muzzleloader | September 12 – September 20 | Doe, Buck |
| 2nd Rifle | October 24 – November 1 | Buck |
| 3rd Rifle | November 7 – November 15 | Buck |
| Private-land only | October 24 – November 15 | Either-sex |
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 71°F, lows around 39°F (mid-elevation normals)
- October — highs around 57°F, lows around 29°F, about 2.1 in of snow (mid-elevation normals)
- November — highs around 43°F, lows around 19°F, about 10 in of snow (mid-elevation normals)
GMU 131 mule deer hunting FAQ
How much of GMU 131 can a public-land hunter actually access?
Roughly 11% of the unit, about 21 square miles, is generally open to public hunting through BLM, State Wildlife Areas, and National Forest. An additional 5.5% is Colorado State Trust Land, but only parcels enrolled in CPW's Public Access Program may be hunted and that enrollment status is unknown. Private land comprises 82% of the unit, making legal access the primary barrier regardless of how walkable the terrain is.
Is this unit realistic for someone with no preference points?
Yes. The unit draws at easy difficulty for the most accessible buck or either-sex hunt code, typically at zero preference points. This describes the easiest unit-wide public-land opportunity for an adult Colorado resident; other seasons, weapons, and nonresident applicants may require more points.
When are mule deer most concentrated in this unit?
Winter Concentration covers only 1% of the unit and occurs during the winter season from January through March. Summer Range spans the entire unit, so mule deer are widely distributed across the hunting seasons in the fall rather than compressed into concentrated areas.
Which season should a public-land hunter focus on here?
The archery season (September 2–30) and muzzleloader season (September 12–20) occur during velvet shed and early fall transition when bucks are shedding antlers and more active. Both are either-sex or doe/buck opportunities, whereas the two rifle seasons that follow are buck-only, which narrows options for hunters seeking either-sex tags.
What role does the small Winter Range play?
Winter Range covers only 7% of the unit, reflecting the moderate elevations here. This does not mean mule deer leave the unit in fall; rather, it indicates they are spread across the broader Summer and Overall Range layers throughout the hunting season, with only a small proportion concentrated on traditional winter grounds by late December.
How much does weather change through the fall hunt?
September averages highs near 71°F, while November averages highs near 43°F, and snowfall increases from essentially zero in September to about 10 inches by November. Hunters should expect a significant cooling trend and plan for snow and shorter daylight hours, particularly in the rifle seasons.
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 — Deer 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) — mule deer 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.