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Colorado GMU 104 elk: terrain, access and seasons

Unit 104's terrain, access, seasons and CPW elk 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 24% for 26 hunters.

Size
1,453 sq mi
CPW unit boundary, 2025
Counties
Denver, Adams, Arapahoe, Douglas, Elbert
Elevation
4,950–7,890 ft
USGS 3DEP, 2026-10-19
Huntable public land
1%
COMaP, 2026-10-12
Second rifle license, 2026
Draw bull
CPW 2026 big game brochure
Success
24%
CPW harvest survey, 2024
Hunters
26
CPW harvest survey, 2024
Hunter-days per sq mi
0.1
CPW, 2024
Road miles, any vehicle
2,313 mi
MVUM + CDOT, open on the Oct 24 opener
Median Habitat Score
0.4 of 5
Ranks 125th of 128 for second rifle. Glassline, v20, 2026-10-19

In short

A low-elevation, open draw-only unit with less far-from-road ground than most units. Most of Unit 104 sits between 5,000 and 6,000 feet, with more grass and meadow than anything else and farmland next. Almost none of the unit is huntable public land. CPW's survey counted 432 hunters across all seasons in 2024, up from 379 in 2022. Every license here is drawn.

Licenses and draw

Second rifle in Unit 104, 2026: a draw bull license (E-M-104-O2-R).

  • E-M-104-O2-R bull, draw 2026 draw: licenses left over for residents and nonresidents

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 104 sits among its neighbors.

391 51 105 461 38 104

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

Conditions

As of Oct 21: no SNOTEL station sits within 6 mi of the unit; severe drought (D2) on the US Drought Monitor over 62.2% of the unit.

Rebuilt nightly; sources at the end of the page.

Item Value Data
SNOTEL No SNOTEL station within 6 mi of the unit
Drought D2, Severe droughtShare of the unit: D0 or worse 99.7% · D1 or worse 87.2% · D2 or worse 62.2% · D3 or worse 9.4% · D4 0.8% 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

Access

Unit 104 has 88 trailheads and about 2,313 miles of road any vehicle may drive on the second rifle opener, plus 57 more that need high clearance. About nine-tenths of the huntable public ground is within a 30-minute walk of a drivable road, and almost none is more than an hour and a half away.

Trailheads
88
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
2,313 mi
High clearance
57 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
89.4%
30–60 min
10.6%
60–90 min
0%
Over 90 min
0%

Hunt codes and draw results

1 hunt code 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
E-M-104-O2-R bull 2024 40 4 11 Leftover 2 2 Leftover
2025 40 4 10 Leftover 6 7 Leftover
2026 40 8 20 Leftover 7 7 Leftover

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 elk have behaved where they were studied, not where they are in Unit 104.

  • In Montana GPS work, rifle-season elk tended to hold about a mile or more from open motorized routes, in blocks of 5,000 acres or more.

    Ranglack et al., 2017 Established finding

  • At Oregon's Starkey Experimental Forest, bulls chose more canopy and kept away from open roads by day during hunts, and the shift was stronger in rifle seasons than in archery.

    Smith et al., 2022 Single study

  • In Montana, collared elk shifted onto ground closed to public hunting once rifle seasons opened, ahead of security cover on public land.

    Proffitt et al., 2013 Established finding

Read next: Colorado second rifle elk, 2026 · How to e-scout a Colorado elk unit

Build a plan for Unit 104, free.

Start free

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

Reference

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

Terrain and habitat

4,950–7,890 ft; grass & meadow 46% and developed 27.9%; no mapped burns since 2020.

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

Elevation Acres per 1,000 ft band. USGS 3DEP.
  1. 4k–5k ft 3,950 ac
  2. 5k–6k ft 534,240 ac
  3. 6k–7k ft 322,620 ac
  4. 7k–8k ft 65,320 ac
Table view
BandAcres
4,000–5,000 ft3,950 ac
5,000–6,000 ft534,240 ac
6,000–7,000 ft322,620 ac
7,000–8,000 ft65,320 ac
Slope Share of the unit per slope class.
  1. Under 5° 81.7%
  2. 5–15° 17%
  3. 15–25° 1.1%
  4. 25–35° 0.2%
  5. 35°+ 0%
Table view
Slope classShare
Flat (under 5°)81.7%
Gentle (5–15°)17%
Moderate (15–25°)1.1%
Steep (25–35°)0.2%
Very steep (35° and up)0%
Aspect Share of non-flat ground facing each way.
  1. N 12.6%
  2. NE 13.4%
  3. E 15.3%
  4. SE 10.7%
  5. S 9.4%
  6. SW 10.6%
  7. W 15.1%
  8. NW 12.8%
Table view
AspectShare
North12.6%
Northeast13.4%
East15.3%
Southeast10.7%
South9.4%
Southwest10.6%
West15.1%
Northwest12.8%
Vegetation LF2024 existing vegetation, groups of 1% or more.
  1. Grass & meadow 46%
  2. Developed 27.9%
  3. Farmland 12.3%
  4. Shrubland 6.9%
  5. Conifer 2.8%
  6. Riparian & wetland 2.8%
Table view
Vegetation groupShare
Grass & meadow46%
Developed27.9%
Farmland12.3%
Shrubland6.9%
Conifer2.8%
Riparian & wetland2.8%
Item Value Data
Burns No burned acres in the unit since 2020 NIFC NIFC
Openings in timber 2,513 openings of 1–40 ac, from lidar covering 99.9% of the unit 2026-10-19 2026-10-19
Habitat Score, second rifle Share of 2,300 ac of huntable public ground in each score band. Median 0.4. Scoring v20, computed 2026-10-19.
Table view
ScoreShare of scored ground
0–0.550.7%
0.5–145.1%
1–1.54.2%
1.5–20%
2–2.50%
2.5–30%
3–3.50%
3.5–40%
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 Castle Rock herd (E-51) estimate for 2025 and hunter density, 2024.

CPW counted 26 second rifle hunters in 2024; on so few, the success rate swings widely from year to year. Across all seasons, hunters rose by just over a tenth between 2022 and 2024. Unit 104 is one of 6 units in CPW's Castle Rock herd unit (E-51), estimated at about 3,500 elk after the 2025 hunt, with 40 bulls per 100 cows.

Hunters, harvest and success
Season Year Hunters Harvest Success
Second rifle 2022 25 5 19%
2023 16 11 67%
2024 26 6 24%
All seasons 2022 379 185 49%
2023 416 220 53%
2024 432 230 53%

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

Item Value Data
Hunter density 2 hunter-days per sq mi, all seasons CPW 2024 CPW 2024
Herd estimate (Castle Rock, E-51) 3,480 post-hunt · 1,930 in 2019 CPW 2025 CPW 2025
Bull:cow ratio 40 bulls per 100 cows 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 Castle Rock herd unit (E-51), which also takes in Units 51, 105, 106, 110 and 111: CPW manages herds, not units. Source: CPW post-hunt population estimate, 2025.

Neighbors

Units 391, 51, 105, 461 and 38, 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. Finding elk is still your job.

Sources

21 datasets and studies, dated where the source dates them.
  1. Elk 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. U.S. Drought Monitor — National Drought Mitigation Center, 2026-10-13
  12. MOD13Q1 vegetation indices (NDVI), 250 m 16-day — NASA LP DAAC, 2026-09-29
  13. Effects of bull age on conception dates and pregnancy rates of cow elk — Noyes, Johnson, Bryant, Findholt and Thomas, Journal of Wildlife Management 60(3), 1996
  14. Security areas for elk during archery and rifle hunting seasons — Ranglack, Proffitt, Canfield, Gude, Rotella and Garrott, Journal of Wildlife Management 81(5), 2017
  15. Behavioral responses of male elk to hunting risk — Smith, Spitz, Brown, Wisdom, Rowland, Forrester, Johnson and Clark, Journal of Wildlife Management 86, 2022
  16. Effects of hunter access and habitat security on elk habitat selection in landscapes with a public and private land matrix — Proffitt, Gude, Hamlin and Messer, Journal of Wildlife Management 77(3), 2013
  17. Plasticity in elk migration timing is a response to changing environmental conditions — Rickbeil, Merkle, Anderson, Atwood, Beckmann, Cole, Courtemanch, Dewey, Gustine, Kauffman, McWhirter, Mong, Proffitt, White and Middleton, Global Change Biology 25, 2019
  18. 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.
  19. SNOTEL network: daily snow depth and snow water equivalent — USDA Natural Resources Conservation Service On the map: SNOTEL stations.
  20. Gazetteer files, places — U.S. Census Bureau, 2024 On the map: towns, 2024.
  21. Species Activity Mapping: elk 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.