Colorado GMU 100 Mule Deer Hunting
Washington and Morgan counties, northeast Colorado · 1,060 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 100 is like
GMU 100 occupies 1,060 square miles of northeastern Colorado in Washington and Morgan counties. The terrain is gentle and rolling, with elevations ranging from 4,200 feet to 5,000 feet and a mean slope of 1.4 degrees. This is plains-and-prairie country with minimal topographic relief, manageable for hunters on foot.
Public hunting ground is extremely limited. Approximately 0.0% of the unit is generally open to public hunting. An additional 6.0% is Colorado State Trust Land, access to which depends on enrollment in CPW's Public Access Program — parcels not enrolled remain unavailable. The remaining 94% is private land. Legal access rather than terrain difficulty is the primary constraint for hunters considering this unit.
Mule deer occupy winter ground across 16% of the unit, with 4% concentrated in designated winter concentration areas. The broader overall range spans the full unit, but this does not indicate year-round occupation across all ground — substantial seasonal shift occurs toward winter range and concentration areas as the fall progresses. A hunter should expect mule deer to concentrate on winter ground and concentration layers as the season advances through late fall and early winter.
The unit offers four seasons. The Archery season runs September 2 to September 30 as an either-sex hunt. The Muzzleloader season spans September 12 to September 20 for does and bucks. Two rifle seasons follow: Plains Early Rifle from October 1 to November 3, available in either-sex or doe-or-buck options, and Plains Late Rifle from December 1 to December 14 for does and bucks. Hunter pressure is low and draw difficulty is easy, often requiring zero preference points for the easiest unit-wide either-sex or buck codes available to adult Colorado residents.
Terrain & elevation
- Elevation
- 4,200–5,000 ft, typically around 4,600 ft
- Steepness
- Gentle — mean slope 1.4°
- Slope breakdown
- 100% gentle · 0% moderate · 0% steep · 0% rugged
- Ground you can count on
- ~0 sq mi, plus ~63 sq mi of State Trust Land where access depends on enrollment
Land & access
About <1% of GMU 100 is public land a hunter can count on. A further 6% is State Trust Land, which is huntable only where CPW has enrolled it.
- BLM<1%
- State Trust Land6%
- Private94%
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 mule deer live in the unit
Colorado Parks & Wildlife maps mule deer seasonal ranges statewide. This is how much of GMU 100 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 Range16%used in winter
- Winter Concentration4%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 |
| Plains Early Rifle | October 1 – November 3 | Either-sex, Doe, Buck |
| Plains Late Rifle | December 1 – December 14 | Doe, 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.
GMU 100 mule deer hunting FAQ
How much public land can a hunter actually hunt on GMU 100?
Approximately 0.0% of the unit is generally open to public hunting. An additional 6.0% is State Trust Land, but only parcels enrolled in CPW's Public Access Program are legally huntable. Most of the unit is private land, making legal access the primary limiting factor regardless of terrain.
Is the terrain in GMU 100 easy to walk?
Yes. The entire unit is gentle and rolling with a mean slope of 1.4 degrees and elevations spanning 4,200 to 5,000 feet. This is plains-and-prairie country with minimal relief, presenting no walking difficulty. Legal access to huntable ground, however, remains a separate and more substantial constraint.
When should a hunter expect mule deer to be concentrated on winter ground?
Winter concentration areas cover 4% of the unit, and winter range extends across 16%. As fall advances into late November and December, mule deer migrate toward and concentrate on this winter ground. Early-season hunts like archery and muzzleloader will contact deer spread more broadly, while late-rifle hunts from early December onward align with the consolidation period and concentration areas.
Which season falls during the mule deer rut?
The Primary Rut occurs November 11 to November 25. Plains Early Rifle (October 1 to November 3) begins before the rut, falling in the Early Fall Migration and Pre-Rut phases. Plains Late Rifle (December 1 to December 14) falls entirely in the Late Rut and Winter Consolidation phases. Archery and Muzzleloader both occur during Velvet Shed and Early Fall Transition in September.
Can a hunter with zero preference points draw GMU 100?
Yes. Draw difficulty is easy, and adult Colorado residents often draw at zero preference points for the easiest available unit-wide either-sex or buck hunts. This is the scope of that statement — other seasons, weapons, and nonresident applicants may require substantially more points.
Is GMU 100 likely to be crowded despite the easy draw?
No. Hunter pressure is low throughout the unit. An easy-to-draw unit can be crowded near a city, but this unit is neither easy to access nor heavily hunted. The combination of limited public land and low hunter pressure means solitude is realistic.
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.