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Colorado GMU 551 mule deer: terrain, access and seasons

Unit 551's terrain, access, seasons and CPW mule deer figures, with Conditions rebuilt nightly.

By Bryson, co-founder Updated

2026 season

Second rifle Oct 24–Nov 1

Every section below follows this season.

Decide

The season's licenses, draw results and harvest figures.

At a glance

Second rifle runs Oct 24–Nov 1, 2026; CPW's 2024 harvest survey put success at 57% for 213 hunters.

Size
546 sq mi
CPW unit boundary, 2025
Counties
Gunnison, Saguache
Elevation
7,820–13,370 ft
USGS 3DEP, 2026-10-19
Huntable public land
87%
COMaP, 2026-10-12
Second rifle license, 2026
Draw buck, doe
CPW 2026 big game brochure. Colorado has no OTC mule deer license
Success
57%
CPW harvest survey, 2024
Hunters
213
CPW harvest survey, 2024
Hunter-days per sq mi
2
CPW, 2024
Road miles, any vehicle
206 mi
MVUM + CDOT, open on the Oct 24 opener
Median Habitat Score
2.1 of 5
Ranks 61st of 156 for second rifle. Glassline, v4, 2026-10-19
Snow now
1 in
Deepest at Porphyry Creek SNOTEL, 2026-10-20

In short

A high-elevation, mostly timbered draw-only unit. Most of Unit 551 sits between 8,000 and 10,000 feet, mostly conifer with shrubland after it; about a tenth of it rises above 11,000 feet. Just under nine-tenths of the unit is huntable public land, and about a tenth of that ground is more than an hour and a half on foot from a drivable road. CPW's survey counted 448 hunters across all seasons in 2024, up from 425 in 2022, while second rifle success fell from 62% to 57%. Every license here is drawn, as for all Colorado mule deer.

Licenses and draw

Second rifle in Unit 551, 2026: a draw buck license (D-M-551-O2-R) and a draw doe license (D-F-551-O2-R).

  • D-M-551-O2-R buck, draw 2026 draw: residents drawn out at 1 point; nonresidents drawn out at 3 points
  • D-F-551-O2-R doe, draw 2026 draw: residents drawn out at 0 points; nonresidents none drawn

CPW 2026 big game brochure; CPW primary-draw recap and drawn-out-at reports, 2024–2026, adult licenses. Every year of draw results is under Hunt codes and draw results.

Plan

The map, Conditions, access, hunt codes and draw results for the season, and what the research says.

Map

The interactive map (public land by manager, roads by vehicle class, burns, trailheads, SNOTEL stations, terrain and CPW's mapped ranges) needs JavaScript. The outline shows where Unit 551 sits among its neighbors.

561 681 56 67 55 551

Public data only. The plan lives in the app. Map sources

Conditions

As of Oct 21: 1 in of snow at Porphyry Creek SNOTEL, the deepest reading near the unit; exceptional drought (D4) on the US Drought Monitor over 46.3% of the unit.

Rebuilt nightly; sources at the end of the page.

Item Value Data
Snow (SNOTEL) Porphyry Creek (10,790 ft): 1 in deep, SWE 0.1 inSargents Mesa (11,490 ft, 0.5 mi out): 0 in deep, SWE 0 inCochetopa Pass (10,020 ft, 3.8 mi out): 0 in deep, SWE 0.1 inSaint Elmo (10,420 ft, 4 mi out): SWE 0.2 in 2026-10-20 2026-10-20
Drought D4, Exceptional droughtShare of the unit: D0 or worse 100% · D1 or worse 100% · D2 or worse 100% · D3 or worse 100% · D4 46.3% USDM 2026-10-13 USDM 2026-10-13
Greenness vs normal, Sep 14–29 112% of the September normal (2014–2023), MODIS 16-day composite 2026-09-29 2026-09-29

7-day forecast

NWS 7-day gridpoint forecast for 8,000–9,000 ft and 10,000–11,000 ft, issued Oct 21; the second rifle opener, Oct 24, is marked; no front named in the NWS discussion for the 7 days.

8,000–9,000 ft NWS GJT gridpoint 164,67, issued 2026-10-21. Gusts and lows: gridpoint only. No front named in the NWS discussion for the 7 days.
Wed 10/21 Thu 10/22 Fri 10/23 Sat 10/24 Opener Sun 10/25 Mon 10/26 Tue 10/27
High / low 58° 27°57° 44°58° 36°54° 34°52° 35°53° 32°53° 31°
Precip 0.1 in0.5 in0.1 in0.2 in0.1 in0 in0 in
Snow 0 in0 in0 in0 in0 in0 in0 in
Gusts 16 mph20 mph26 mph22 mph17 mph10 mph14 mph
10,000–11,000 ft NWS GJT gridpoint 165,68, issued 2026-10-21. Gusts and lows: gridpoint only. No front named in the NWS discussion for the 7 days.
Wed 10/21 Thu 10/22 Fri 10/23 Sat 10/24 Opener Sun 10/25 Mon 10/26 Tue 10/27
High / low 54° 30°52° 40°53° 36°49° 32°46° 32°47° 30°48° 28°
Precip 0.1 in0.5 in0.1 in0.2 in0.1 in0 in0 in
Snow 0 in0 in0 in0 in0.4 in0 in0 in
Gusts 16 mph21 mph25 mph21 mph20 mph10 mph14 mph

Access

Unit 551 has 6 trailheads and about 206 miles of road any vehicle may drive on the second rifle opener, plus 248 more that need high clearance. About three-fifths of the huntable public ground is within a 30-minute walk of a drivable road, and about a tenth is more than an hour and a half away.

Trailheads
6
COTREX, computed 2026-10-19
Road miles open, second rifle opener Oct 24–Nov 1, by the smallest vehicle allowed. MVUM plus county and state roads.
Vehicle Miles
Any vehicle
206 mi
High clearance
248 mi
4x4
0 mi
Walking time from a drivable road Share of huntable public ground by foot time from the nearest drivable road. Foot time at a standard pace on Glassline's travel model (slope, vegetation, trails), from the nearest highway, road a high-clearance vehicle can drive, or trailhead, with every road open.
Walking time Share
Within 30 min
59.4%
30–60 min
18.9%
60–90 min
12.9%
Over 90 min
8.8%

Hunt codes and draw results

2 hunt codes for second rifle, 2026, with CPW's primary-draw results for 2024–2026.

Hunt code Year Licenses Residents Nonresidents
1st-choice applicants Drawn Drawn out at 1st-choice applicants Drawn Drawn out at
D-M-551-O2-R buck 2024 180 209 98 1 point 116 34 2 points
2025 180 186 97 1 point 121 36 3 points
2026 190 241 108 1 point 149 34 3 points
D-F-551-O2-R doe 2024 80 94 58 0 points 7 6 0 points
2025 30 80 8 1 point 3 1 3 points
2026 50 47 33 0 points 1 0 None Drawn

Hunt codes from the CPW 2026 big game brochure. A code valid in several units counts every hunter in all of them.

Draw results are CPW's primary-draw recap and drawn-out-at reports, 2024–2026, adult licenses. "Drawn out at" is the lowest preference-point level that drew a license; "Leftover" means licenses remained after the draw. A code valid in several units counts every applicant for all of them. Source: CPW draw reports, 2024–2026.

What the research says for this season

Findings from published studies and agency work, as tendencies. They describe how mule deer have behaved where they were studied, not where they are in Unit 551.

  • In a south-central Wyoming herd, mature bucks moved away from motorized routes into roadless cover during a rifle season while does stayed on their usual forage, and hunting barely changed when deer migrated.

    Rodgers et al., 2021 Single study

  • In Colorado's Gunnison Basin, GPS-collared mule deer made their fall migration from late October into early November, along corridors averaging about 17 miles.

    Kauffman et al., 2024 Single study

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Reference

Terrain, the multi-year numbers, neighbors and sources. Each opens in place.

Terrain and habitat

7,820–13,370 ft; conifer 53.1% and shrubland 29.4%; no mapped burns since 2020.

Unit-wide figures, computed 2026-10-19.

Elevation Acres per 1,000 ft band. USGS 3DEP.
  1. 7k–8k ft 3,410 ac
  2. 8k–9k ft 105,520 ac
  3. 9k–10k ft 113,520 ac
  4. 10k–11k ft 88,450 ac
  5. 11k–12k ft 31,630 ac
  6. 12k–13k ft 4,890 ac
Table view
BandAcres
7,000–8,000 ft3,410 ac
8,000–9,000 ft105,520 ac
9,000–10,000 ft113,520 ac
10,000–11,000 ft88,450 ac
11,000–12,000 ft31,630 ac
12,000–13,000 ft4,890 ac
Slope Share of the unit per slope class.
  1. Under 5° 15.8%
  2. 5–15° 37.9%
  3. 15–25° 32.4%
  4. 25–35° 12.6%
  5. 35°+ 1.3%
Table view
Slope classShare
Flat (under 5°)15.8%
Gentle (5–15°)37.9%
Moderate (15–25°)32.4%
Steep (25–35°)12.6%
Very steep (35° and up)1.3%
Aspect Share of non-flat ground facing each way.
  1. N 11.4%
  2. NE 10.3%
  3. E 10.7%
  4. SE 10.3%
  5. S 11.6%
  6. SW 14.1%
  7. W 16.4%
  8. NW 15.1%
Table view
AspectShare
North11.4%
Northeast10.3%
East10.7%
Southeast10.3%
South11.6%
Southwest14.1%
West16.4%
Northwest15.1%
Vegetation LF2024 existing vegetation, groups of 1% or more.
  1. Conifer 53.1%
  2. Shrubland 29.4%
  3. Aspen 5.8%
  4. Grass & meadow 3%
  5. Farmland 2.7%
  6. Rock & scree 2%
  7. Riparian & wetland 2%
Table view
Vegetation groupShare
Conifer53.1%
Shrubland29.4%
Aspen5.8%
Grass & meadow3%
Farmland2.7%
Rock & scree2%
Riparian & wetland2%
Item Value Data
Burns No burned acres in the unit since 2020 NIFC NIFC
Openings in timber 1,111 openings of 1–40 ac, from lidar covering 97.9% of the unit 2026-10-19 2026-10-19
Habitat Score, second rifle Share of 302,400 ac of huntable public ground in each score band. Median 2.1. Scoring v4, computed 2026-10-19.
Table view
ScoreShare of scored ground
0–0.50%
0.5–10.4%
1–1.58.3%
1.5–230.1%
2–2.539.1%
2.5–318.6%
3–3.53.2%
3.5–40.2%
4–4.50%
4.5–50%

Glassline's Habitat Score grades terrain and habitat for the season on food, water, breeding and shelter. Shown here as one distribution for the whole unit, never a map: it grades ground, not animal locations.

The numbers

CPW harvest estimates 2022–2024 for the chosen season and all seasons, the Gunnison Basin herd (D-57) estimate for 2025 and hunter density, 2024.

Second rifle success fell from 62% to 57% between 2022 and 2024, while the season's hunters fell by about a tenth. Across all seasons, hunters held about steady between 2022 and 2024. Unit 551 is one of 5 units in CPW's Gunnison Basin mule deer herd (DAU D-57), estimated at about 19,000 mule deer after the 2025 hunt, with 40 bucks per 100 does.

Hunters, harvest and success
Season Year Hunters Harvest Success
Second rifle 2022 243 150 62%
2023 245 148 61%
2024 213 121 57%
All seasons 2022 425 272 64%
2023 469 275 59%
2024 448 243 54%

CPW deer harvest reports, 2022–2024. A dash: not reported.

Item Value Data
Hunter density 4 hunter-days per sq mi, all seasons CPW 2024 CPW 2024
Herd estimate (Gunnison Basin, D-57) 18,730 post-hunt · 18,510 in 2023 CPW 2025 CPW 2025
Buck:doe ratio 40 bucks per 100 does CPW 2025 CPW 2025

CPW harvest figures are survey estimates, not counts, and they cover the whole unit, private land included. Source: CPW harvest reports, 2022–2024.

Herd numbers cover the whole Gunnison Basin herd unit (D-57), which also takes in Units 54, 55, 66 and 67: CPW manages herds, not units. Source: CPW post-hunt population estimate, 2025.

Neighbors

Units 561, 681, 56, 67 and 55, nearest first.

From each unit's own page; dates there.

What this page can't tell you

Closures, private ground, this year's pressure and animal locations.
  • Closures. Forest, fire and road closure orders change through the season and aren't checked here. The managing agency's current order governs.
  • Private ground. Land with no public hunting access is hunted only with the owner's permission, and the public-land share above leaves it out.
  • This year's pressure. CPW's hunter numbers run a year or more behind the season you're planning.
  • Animal locations. These are terrain, access, harvest and herd figures, and CPW's mapped ranges are range lines; none of them places an animal.

Sources

23 datasets and studies, dated where the source dates them.
  1. Deer statistics: population estimates and harvest reports — Colorado Parks and Wildlife
  2. Colorado big game hunting: brochure, seasons and hunt codes — Colorado Parks and Wildlife
  3. Game Management Unit boundaries (Hunting Atlas) — Colorado Parks and Wildlife On the map: unit boundaries, 2025.
  4. COMaP: Colorado Ownership, Management and Protection — Colorado Natural Heritage Program, 2026-10-12 On the map: public land by manager, mapped 2026-07-29.
  5. 3D Elevation Program (3DEP), 1/3 arc-second — U.S. Geological Survey On the map: shaded relief from 5 m and 10 m lidar elevation, mapped 2026-10-04; elevation bands and slope, mapped 2026-10-04.
  6. LANDFIRE Existing Vegetation Type (LF 2024) — U.S. Geological Survey / USDA Forest Service, LF2024
  7. 3DEP lidar point clouds (canopy height model) — U.S. Geological Survey
  8. COTREX: Colorado Trail Explorer — Colorado Parks and Wildlife On the map: trailheads, 2024.
  9. Motor Vehicle Use Maps (MVUM) — USDA Forest Service On the map: roads by vehicle class, drawn as open on the selected season's opener, mapped 2026-08-22.
  10. Highways and major roads — Colorado Department of Transportation On the map: highways, mapped 2026-07-31.
  11. SNOTEL network: daily snow depth and snow water equivalent — USDA Natural Resources Conservation Service, 2026-10-20 On the map: SNOTEL stations.
  12. U.S. Drought Monitor — National Drought Mitigation Center, 2026-10-13
  13. MOD13Q1 vegetation indices (NDVI), 250 m 16-day — NASA LP DAAC, 2026-09-29
  14. National Weather Service 7-day gridpoint forecast — National Weather Service, 2026-10-21
  15. National Weather Service Area Forecast Discussion (BOU, GJT, PUB) — National Weather Service, 2026-10-21
  16. Influence of well pad activity on winter habitat selection patterns of mule deer — Sawyer, Kauffman and Nielson, Journal of Wildlife Management 73(7), 2009
  17. Sex-specific behaviors of hunted mule deer during rifle season — Rodgers, Sawyer, Mong, Stephens and Kauffman, Journal of Wildlife Management 85(2), 2021
  18. Ungulate migrations of the western United States, volume 4 — Kauffman, Lowrey, Beaupre and others, USGS Scientific Investigations Report 2024-5006, 2024
  19. Mule deer (Odocoileus hemionus) fact sheet — USDA Natural Resources Conservation Service, Colorado, Fact sheet, March 2000, 2000
  20. Timing of seasonal migration in mule deer: effects of climate, plant phenology, and life-history characteristics — Monteith, Bleich, Stephenson, Pierce, Conner, Klaver and Bowyer, Ecosphere 2(4), 2011
  21. Wildland Fire Interagency Geospatial Services (WFIGS) fire perimeters — National Interagency Fire Center On the map: burns over 100 acres since 2020, mapped 2026-06-29.
  22. Gazetteer files, places — U.S. Census Bureau, 2024 On the map: towns, 2024.
  23. Species Activity Mapping: mule deer seasonal ranges — Colorado Parks and Wildlife, 2025 On the map: CPW mapped ranges, 2025.

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POIs are terrain candidates — places worth checking, not animal locations.