Colorado GMU 40 Mule Deer Hunting
Mesa County, southwest Colorado · 742 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 40 is like
GMU 40 spans 742 square miles in Mesa County across the Colorado Plateau's transition zone, with elevations ranging from 4,300 feet to 9,700 feet and a typical mid-unit elevation around 6,700 feet. The terrain is rolling, with some steeper breaks: 59% of the unit is gentle, 26% moderate, and 12% steep, with 3% rugged. The unit's moderate mean slope of 12.2 degrees reflects this mixed topography, offering a mix of easier and more demanding country for foot hunters.
Public hunting is available on roughly 58% of the unit—approximately 428 square miles of BLM, National Forest, and State Wildlife Areas. An additional 4.3% is National Park Service land, which is closed to hunting. The remaining 38% is private ground. This public-land share creates genuine opportunities for access, though roads, trailheads, seasonal closures, and private inholdings still govern where a hunter can actually reach the ground.
Mule deer seasonal range across the unit reflects typical fall movement patterns. Winter Range covers 73% of the unit, with 14% classified as Winter Concentration ground where deer cluster; this substantial concentration layer indicates deer do not spread evenly across winter habitat but rather aggregate in preferred areas. Summer Range covers 37% of the unit, and Migration Corridors account for 3%. As fall progresses from September through November, temperatures cool from typical highs around 76°F in September to around 48°F by November, with snowfall increasing from near zero in September to around 1.5 inches monthly by November. This seasonal cooling and increasing snow typically drive deer from Summer Range toward Winter Range as the season advances, though timing and extent vary with weather and snow conditions.
GMU 40 offers five public-land hunting seasons for mule deer: Archery (September 2–September 30), Muzzleloader (September 12–September 20), 2nd Rifle (October 24–November 1), 3rd Rifle (November 7–November 15), and 4th Rifle (November 18–November 22). All seasons are for bucks. The Archery and Muzzleloader seasons fall during Velvet Shed / Early Fall Transition, when bucks are shedding velvet and behavior is changing. The 2nd Rifle season spans Early Fall Migration / Nocturnal Buck Phase and Early Pre-Rut / Migration Corridor Staging, as bucks become active and move toward rutting grounds. The 3rd Rifle season overlaps Early Pre-Rut / Migration Corridor Staging and Primary Rut, with the rut reaching full intensity in the final days of the season. The 4th Rifle season coincides with Primary Rut. Draw difficulty for this unit is rated Hard, requiring 3–5 preference points for the easiest unit-wide buck hunt available to adult Colorado residents. Hunter pressure is Low overall.
Terrain & elevation
- Elevation
- 4,300–9,700 ft, typically around 6,700 ft
- Steepness
- Moderate — mean slope 12.2°
- Slope breakdown
- 59% gentle · 26% moderate · 12% steep · 3% rugged
- Ground you can count on
- ~428 sq mi
Land & access
About 58% of GMU 40 is public land a hunter can count on — BLM, National Forest and State Wildlife Areas. Another 4% is public but closed to hunting — National Park Service.
- BLM56%
- National Forest2%
- State Wildlife Area<1%
- National Park Service4%
- Unclassified ownership<1%
- Private38%
Where mule deer live in the unit
Colorado Parks & Wildlife maps mule deer seasonal ranges statewide. This is how much of GMU 40 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%.
- 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 Range73%used in winter
- Summer Range37%used in summer
- Winter Concentration14%where mule deer bunch up in winter
- Migration Corridors3%movement between ranges, not residence
Mule Deer seasons & weapons (2026)
| Season | Dates | Tags offered |
|---|---|---|
| Archery | September 2 – September 30 | Buck |
| Muzzleloader | September 12 – September 20 | Buck |
| 2nd Rifle | October 24 – November 1 | Buck |
| 3rd Rifle | November 7 – November 15 | Buck |
| 4th Rifle | November 18 – November 22 | Buck |
| Private-land only | October 24 – November 15 | Buck |
| Ranching for Wildlife | Dates vary by hunt code | Buck |
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 76°F, lows around 49°F (mid-elevation normals)
- October — highs around 62°F, lows around 37°F, about 0.5 in of snow (mid-elevation normals)
- November — highs around 48°F, lows around 26°F, about 1.5 in of snow (mid-elevation normals)
GMU 40 mule deer hunting FAQ
How much public land can a hunter actually count on hunting here?
Roughly 58% of the unit, or 428 square miles, is open to public hunting on BLM, National Forest, and State Wildlife Areas. An additional 4.3% is National Park Service land, which is closed to hunting. The remaining 38% is private. Whether a hunter can reach the open ground depends on road access, trailhead locations, private inholdings, and seasonal closures, which vary across the unit.
Is this unit realistic for someone with no preference points?
No. The draw difficulty is rated Hard, requiring 3–5 preference points for the easiest unit-wide buck hunt available to adult Colorado residents. Applicants with zero points should plan to build preference before applying, or investigate private-land-only or Ranching for Wildlife opportunities, which operate under different drawing systems.
Which season offers the best chance at a rutting buck?
The 3rd Rifle season (November 7–November 15) and especially the 4th Rifle season (November 18–November 22) coincide with Primary Rut, when buck behavior is most predictable. The 3rd Rifle season straddles the transition into full rut, while the 4th Rifle season occurs entirely within Primary Rut—the peak window for intercepting active bucks.
Where do mule deer concentrate in winter?
Mule deer occupy Winter Range across 73% of the unit, with 14% classified as Winter Concentration ground where they cluster in preferred areas. The concentration layer does not identify specific locations—hunters must scout to find where deer actually aggregate—but it indicates that deer do not distribute evenly across available winter habitat.
Will the weather get harder as the season progresses?
Yes. September highs average around 76°F with negligible snow; by November, highs drop to around 48°F and snowfall averages 1.5 inches per month. October sits between the two, with highs around 62°F and about 0.5 inches of snow. Later seasons offer colder conditions and increasing snow, which typically intensify deer movement toward winter range.
Is this unit better for early-season or late-season hunting?
That depends on the hunter's style. Archery and Muzzleloader seasons (early September) occur during Velvet Shed / Early Fall Transition, when bucks are transitioning behavior but not yet in rut—requiring active hunting. Rifle seasons from late October onward span pre-rut and primary rut phases, when buck behavior becomes more concentrated and predictable. Early seasons demand more skill; later seasons offer higher rut activity but colder conditions and more hunter presence.
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.