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
Game Management Unit 131 spans 193 square miles across Routt and Rio Blanco counties in northwestern Colorado. The unit's elevation ranges from 6,500 feet to 9,100 feet, with typical ground around 7,300 feet. Terrain is rolling, with some steeper breaks — 51% of the unit is gentle, 39% is moderate, and 10% is steep. The country supports mule deer across the full range of mapped seasonal ranges, with Summer Range covering 100% of the unit.
Public hunting access is limited. Generally open public land—managed by the Bureau of Land Management, Colorado Parks and Wildlife State Wildlife Areas, and the US Forest Service—comprises only 11% of the unit, roughly 21 square miles. An additional 5.5% is Colorado State Trust Land, huntable only where parcels are enrolled in CPW's Public Access Program; which parcels are available is not specified here and varies by year. Private land covers 82% of the unit. Ownership of 1.6% is unclassified. Legal access, not terrain walkability, is the primary constraint on hunting opportunity in this unit.
Mule deer distribution shifts through the fall. Summer Range covers the full unit through early fall, but Winter Range covers only 7% and Winter Concentration covers 1%, indicating concentrated mule deer use on limited ground as the season advances. A hunter should expect deer to shift toward wintering ground as temperatures drop and snow accumulates; timing and extent of this movement vary with weather. Archery and Muzzleloader seasons fall during the Velvet Shed / Early Fall Transition phase when deer still occupy summer range widely. The two rifle seasons—2nd Rifle in late October and 3rd Rifle in early-to-mid November—span the Early Fall Migration / Nocturnal Buck Phase and Early Pre-Rut / Migration Corridor Staging phases, including the Primary Rut in mid-to-late November.
The unit offers five seasons total. Four are available to public hunters: Archery September 2–September 30 (Either-sex), Muzzleloader September 12–September 20 (Doe/Buck), 2nd Rifle October 24–November 1 (Buck), and 3rd Rifle November 7–November 15 (Buck). One season—October 24–November 15, Either-sex—is private-land only. September conditions bring highs around 71°F and negligible snowfall. October cools to highs around 57°F with roughly 2.1 inches of monthly snowfall. November drops to highs near 43°F with approximately 10 inches of monthly snowfall. Overall hunter pressure is extreme. The unit draws at the easier end of the difficulty range, often at zero preference points, based on the most accessible unit-wide buck or either-sex code available to adult Colorado residents.
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
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
Is this unit realistic for a hunter with no preference points?
Yes. The unit draws at the easier end of the difficulty spectrum, often at zero preference points, for the most accessible unit-wide buck or either-sex codes available to adult Colorado residents. However, extreme hunter pressure means that even with a tag, finding unhunted ground will be challenging given that only 11% of the unit is dependably open to public hunting.
How much ground can a public-land hunter actually access?
Only about 11% of the unit—roughly 21 square miles of BLM, State Wildlife Areas, and National Forest—is generally open to public hunting. An additional 5.5% is State Trust Land, but it is huntable only where CPW has enrolled specific parcels in the Public Access Program, and enrollment varies. Legal access, not ease of terrain, is the limiting factor here.
Is archery or rifle a better fit for this unit's rut timing?
Archery and Muzzleloader both occur during the Velvet Shed / Early Fall Transition phase in early September, when deer are still distributed across summer range. The two rifle seasons—2nd Rifle in late October and 3rd Rifle in early November—overlap the Early Pre-Rut / Migration Corridor Staging phase and the Primary Rut in mid-to-late November, making rifle seasons better aligned with rut hunting.
What happens to deer distribution as the season progresses?
Summer Range covers the full unit through early fall, but Winter Range covers only 7% of the unit. A hunter should expect deer to concentrate on a smaller portion of ground as temperatures drop and snowfall accumulates through November, though the timing and extent of movement vary with weather and snow.
How steep is the terrain, and is it manageable for a hunter on foot?
The unit is rolling with some steeper breaks: 51% is gentle, 39% is moderate, and only 10% is steep. Most of the unit is walkable for a reasonably fit hunter. Terrain walkability, however, is separate from the challenge of legal access; limited public land availability is the real constraint.
Does extreme hunter pressure mean the draw is very competitive?
Draw difficulty and hunter pressure are different things. This unit draws easily, often at zero preference points, for the most accessible unit-wide codes—but it receives extreme hunter pressure, meaning that even tag-holders will encounter many other hunters in the field. An easy draw does not mean uncrowded hunting.
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
- 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
- Federal and state land-ownership datasets — land ownership and access
- NOAA climate normals — 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 August 31, 2026.