Colorado GMU 21 Elk Hunting

Q: How much of this unit can a public-land hunter actually access and hunt?

Approximately 776 square miles, or 87% of the unit, is BLM land that is generally open to public hunting. An additional 0.6% is State Wildlife Area. The remaining 12% is private land, and 0.1% is State Trust Land where CPW has specific enrollments. Public ownership alone is substantial, though hunters should verify road and trailhead access before committing, as ownership does not guarantee convenient entry.

Q: Is this unit realistic for someone applying with zero or very few preference points?

Yes. The unit draws as Easy and often requires zero preference points for the most accessible adult Colorado resident bull or either-sex hunts, such as the 4th Rifle either-sex season. Other seasons and weapon choices, as well as nonresident applicants, may require more points. The low draw difficulty reflects the available opportunity across the multiple seasons offered.

Q: When should a hunter plan to hunt this unit—early or late fall?

Archery and muzzleloader seasons in early September fall during rut onset and primary rut, when bulls are vocal and active. The four rifle seasons stretch from mid-October through late November, spanning post-rut recovery and migration transition phases. Early seasons suit hunters targeting rutting behavior; later seasons occur as temperatures drop sharply, with November highs falling from ~46°F, and snow accumulation increases. Weather and elk behavior both shift notably across the fall.

Q: Does terrain on this unit make it manageable for a hunter on foot?

The unit's terrain is mixed. Roughly 34% is gentle and 48% is moderate, providing significant country that does not demand extreme fitness or scrambling. However, 17% is steep and 1% is rugged, so hunters should expect varied challenges depending on where they concentrate their effort. The rolling-to-moderately-steep character accommodates different abilities, but specific route-finding matters.

Q: Does the elk herd shift toward private ground as the fall progresses?

CPW maps Resident Population across 30% of the unit, indicating year-round presence, so elk are not expected to leave entirely. Winter Range covers 90% of the unit, and Winter Concentration is marked across 21%, so elk do cluster in response to season and weather rather than departing. However, precise timing and extent of any movement vary with snowfall and conditions, and private-land patterns are not documented in the CPW data for this unit.

Q: What does the 'Easy' draw-difficulty rating mean for this unit?

The Easy rating reflects the lowest preference-point tier for the most accessible adult Colorado resident bull or either-sex hunts—typically zero points for certain seasons. It applies specifically to the easiest qualifying option and does not cover all weapons, seasons, or applicant types; nonresident applicants or other seasons may require substantially more points. The rating is a floor for opportunity, not a ceiling on demand.

Rio Blanco and Garfield counties, northwest Colorado · 888 sq mi

Draw difficulty

Easy — often 0 points

Elevation

5,100–9,100 ft

Terrain (avg slope)

Steep · 15.6°

Open to hunting

87%

Hunter pressure

Low

Based on the EASIEST unit-wide bull 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 21 is like

Colorado GMU 21 spans 888 square miles across Rio Blanco and Garfield counties in the northwest region. The country is rolling to moderately steep, with elevations ranging from 5,100 feet in the valleys to 9,100 feet at the high points, and typical hunting elevation around 6,500 feet. Terrain breaks down as 34% gentle, 48% moderate, 17% steep, and 1% rugged. The unit offers mixed country suitable for hunters willing to cover moderate ground, with access to both rolling lower-elevation areas and steeper high country.

BLM land comprises 87% of the unit, and State Wildlife Areas make up 0.6%, creating approximately 776 square miles of generally open ground available to public hunters. The remaining land is about 12% private and 0.1% State Trust Land. This composition allows substantial public access across the unit, though private inholdings and specific access points require verification before hunting.

Elk occupy a year-round presence across 30% of the unit as Resident Population, meaning that portion experiences use throughout the fall and beyond. Summer Range and Winter Range each cover about 29% and 90% of the unit respectively, reflecting expected seasonal shifts. Winter Concentration ground covers 21% of the unit where elk cluster during winter months, while Summer Concentration accounts for 20%, indicating that elk do not distribute evenly across available range. Migration Corridors occupy 1% of the unit. A hunter should expect elk to be present throughout the fall, with concentration patterns varying by season and weather conditions.

The unit offers six seasons open to public hunters across multiple weapons. Archery runs September 2 through September 30 and is either-sex or antlerless. Muzzleloader runs September 12 through September 20, also either-sex or antlerless. There are four rifle seasons: 1st Rifle October 14–18 (either-sex, antlerless, or bull); 2nd Rifle October 24 through November 1 (antlerless); 3rd Rifle November 7–15 (antlerless); and 4th Rifle November 18–22 (either-sex, antlerless, or bull). The fall season spans the rut onset and primary rut in early September through the post-rut recovery and migration transition phases into November. The unit draws as Easy, often requiring zero preference points for the most accessible bull or either-sex hunts open to adult Colorado residents. Overall hunter pressure is low.

Terrain & elevation

Elevation: 5,100–9,100 ft, typically around 6,500 ft
Steepness: Steep — mean slope 15.6°
Slope breakdown: 34% gentle · 48% moderate · 17% steep · 1% rugged
Ground you can count on: ~776 sq mi, plus ~1 sq mi of State Trust Land where access depends on enrollment

Land & access

About 87% of GMU 21 is public land a hunter can count on — BLM and State Wildlife Areas.

Generally open to public hunting

BLM87%
State Wildlife Area<1%

Public land, access depends on enrollment

State Trust Land<1%

Private

Private12%

Where elk live in the unit

Colorado Parks & Wildlife maps elk seasonal ranges statewide. This is how much of GMU 21 each range covers — the single best clue to whether elk 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 elk — near 100% on most units, and not a statement about when elk are present
Winter Range90%
used in winter
Resident Population30%
the only layer that means year-round use
Summer Range29%
used in summer
Winter Concentration21%
where elk bunch up in winter
Summer Concentration20%
where elk bunch up in summer
Migration Corridors1%
movement between ranges, not residence

Elk seasons & weapons (2026)

Season	Dates	Tags offered
Archery	September 2 – September 30	Either-sex, Antlerless
Muzzleloader	September 12 – September 20	Either-sex, Antlerless
1st Rifle	October 14 – October 18	Either-sex, Antlerless, Bull
2nd Rifle	October 24 – November 1	Antlerless
3rd Rifle	November 7 – November 15	Antlerless
4th Rifle	November 18 – November 22	Either-sex, Antlerless, Bull
Private-land only	September 2 – October 18	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 75°F, lows around 46°F (mid-elevation normals)
October — highs around 61°F, lows around 35°F, about 0.7 in of snow (mid-elevation normals)
November — highs around 46°F, lows around 24°F, about 1.6 in of snow (mid-elevation normals)

GMU 21 elk hunting FAQ

How much of this unit can a public-land hunter actually access and hunt?

Approximately 776 square miles, or 87% of the unit, is BLM land that is generally open to public hunting. An additional 0.6% is State Wildlife Area. The remaining 12% is private land, and 0.1% is State Trust Land where CPW has specific enrollments. Public ownership alone is substantial, though hunters should verify road and trailhead access before committing, as ownership does not guarantee convenient entry.

Is this unit realistic for someone applying with zero or very few preference points?

Yes. The unit draws as Easy and often requires zero preference points for the most accessible adult Colorado resident bull or either-sex hunts, such as the 4th Rifle either-sex season. Other seasons and weapon choices, as well as nonresident applicants, may require more points. The low draw difficulty reflects the available opportunity across the multiple seasons offered.

When should a hunter plan to hunt this unit—early or late fall?

Archery and muzzleloader seasons in early September fall during rut onset and primary rut, when bulls are vocal and active. The four rifle seasons stretch from mid-October through late November, spanning post-rut recovery and migration transition phases. Early seasons suit hunters targeting rutting behavior; later seasons occur as temperatures drop sharply, with November highs falling from ~46°F, and snow accumulation increases. Weather and elk behavior both shift notably across the fall.

Does terrain on this unit make it manageable for a hunter on foot?

The unit's terrain is mixed. Roughly 34% is gentle and 48% is moderate, providing significant country that does not demand extreme fitness or scrambling. However, 17% is steep and 1% is rugged, so hunters should expect varied challenges depending on where they concentrate their effort. The rolling-to-moderately-steep character accommodates different abilities, but specific route-finding matters.

Does the elk herd shift toward private ground as the fall progresses?

CPW maps Resident Population across 30% of the unit, indicating year-round presence, so elk are not expected to leave entirely. Winter Range covers 90% of the unit, and Winter Concentration is marked across 21%, so elk do cluster in response to season and weather rather than departing. However, precise timing and extent of any movement vary with snowfall and conditions, and private-land patterns are not documented in the CPW data for this unit.

What does the 'Easy' draw-difficulty rating mean for this unit?

The Easy rating reflects the lowest preference-point tier for the most accessible adult Colorado resident bull or either-sex hunts—typically zero points for certain seasons. It applies specifically to the easiest qualifying option and does not cover all weapons, seasons, or applicant types; nonresident applicants or other seasons may require substantially more points. The rating is a floor for opportunity, not a ceiling on demand.

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 — Elk 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) — elk 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 28, 2026.

Nearest Colorado elk units

GMU 22 GMU 10 GMU 31 GMU 30 GMU 11 GMU 32

← All Colorado elk units