Unit S37 (St.. Vrain)
Colorado Hunting Guide — Bighorn Sheep
Unit S37 lies in Boulder, Grand and Larimer counties. CPW bounds it by RMNP boundary and U.S. 36 among others. CPW's harvest estimates put bighorn sheep success here as high as 100%. Federal land covers about 77% of it. Check land status on a current map before you plan a route.
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Bighorn Sheep Hunting in Unit S37
Unit S37 lies in Boulder, Grand and Larimer counties. CPW bounds it by RMNP boundary and U.S. 36 among others. CPW's harvest estimates put bighorn sheep success here as high as 100%. Federal land covers about 77% of it. Check land status on a current map before you plan a route.
Where to Find Bighorn Sheep in Unit S37
What CPW publishes for unit S37 is a boundary, not a bighorn sheep map. The country below is verified; where to begin in it is our judgement, not the agency's. The unit lies in Boulder, Grand and Larimer counties.
The lines of the unit: RMNP boundary, U.S. 36 and Boulder CRs 94
CPW has unit S37 bounded on the north and east by RMNP boundary and U.S. 36; on the south by Boulder CRs 94, 81, 106 and 95 (Lefthand Canyon Drive), Colo. 72 (Peak to Peak Highway), Boulder CR 102 (Brainard Lake Rd.), USFS Trail 907 (Pawnee Pass Trail) and USFS Trail 1 (Cascade Creek Trail); on the west by USFS 125, USFS Trail 102 (Knight Ridge Trail) and RMNP boundary. It tells you the shape of the unit and nothing about its inhabitants. Its value is practical — those are the features you will navigate by, and the ridges that separate one day's country from another's.
High ground inside the line: Mount Audubon, Paiute Peak and Mount Toll
Named high points inside the unit include Mount Audubon at 13,207 feet, Paiute Peak at 13,050 feet, Mount Toll at 12,965 feet, Pawnee Peak at 12,941 feet and Little Pawnee Peak at 12,446 feet. Several carry a public-land flag in our data, which makes them the first places to try for a view. Sheep need rock to escape into and will not stand far from it.
Holding ground: Chipmunk Gulch, Peck Gulch and East Gorge Canyon
Below them sit Chipmunk Gulch at 8,799 feet, Peck Gulch at 8,734 feet, East Gorge Canyon at 8,724 feet, Hermit Park at 8,447 feet and Tahosa Valley at 8,310 feet. Those are the basins, parks and bottoms this unit has, and they are what you glass into from above. Work out which of them you can see from one position before you pick a camp.
Public ground to start from: Twin Sisters SWA
CPW lists Twin Sisters SWA inside this unit as ground open to public hunting. Each property sets its own restrictions, and the agency's page for it is where they are written down. Federal land covers about 77% of the unit on top of those.
The herd this unit belongs to: RBS-02
CPW does not manage bighorn sheep unit by unit. It manages them as data analysis unit RBS-02, and unit S37 is one piece of it. The rest of RBS-02 is unit S19 and unit S57. Read a neighbour in the same herd before you read the state average — the herd, not the unit line, is what the agency is steering.
Unit S37 terrain and land status
Measured from the unit boundary, not from the agency write-up
Named features inside the unit
Glass from: Mount Audubon (13,207 ft), Hiamovi Mountain (12,350 ft), Sawtooth Mountain (12,297 ft), Thunderbolt Peak (11,920 ft)
Holding ground: Buchanan Pass (11,846 ft), Pierson Park (9,047 ft), Peck Gulch (8,734 ft), Twin Sisters SWA
Every one of these was tested against the unit polygon before it went on the map. They are starting points, not agency recommendations.
How to Hunt Bighorn Sheep in Unit S37
Bighorn Sheep Success Rates
CPW's 2023 harvest estimates put bighorn sheep success in unit S37 at 100% — 2 animals taken by 2 hunters. On a sample that small the percentage moves several points with one animal, so read the hunter count beside it.
These are the agency's own printed figures for this unit, not a modelled estimate and not a state average. They describe one season, so check CPW's current harvest estimates before you read a trend into them.
Bighorn Sheep Draw Odds
| Season | Tags | Applicants | Draw % | Pts Req |
|---|---|---|---|---|
| Archery — 1st Season ram only (resident) | 1 | 41 | 2.4% | 3 |
| Archery — 1st Season ram only (nonresident) | 0 | 0 | 0.0% | — |
| Rifle — 1st Season ram only (resident) | 1 | 69 | 1.4% | 3 |
| Rifle — 1st Season ram only (nonresident) | 0 | 0 | 0.0% | — |
Data from 2026 draw results. Each row is one residency pool — read the label before the number.
Open in Draw Odds EngineCPW's 2026 draw recap for bighorn sheep in unit S37, by hunt code, with resident and nonresident kept apart because the two draw from different licence pools:
- SMS37O1R — Rifle, 1st Season, Ram Only, resident: 69 applicants for 1 licences, 1.4% drawn, 3 preference points needed
- SMS37O1A — Archery, 1st Season, Ram Only, resident: 41 applicants for 1 licences, 2.4% drawn, 3 preference points needed
Colorado runs a pure preference-point draw, so the point figure above is the requirement the agency published for that code in that year, not a forecast for the next one. Figures checked against CPW's own statistics pages on 2026-06-09.
Unit Logistics & Expectations
Frequently Asked Questions
Where is Colorado unit S37?
What is the bighorn sheep success rate in unit S37?
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Upgrade to Pro — $49/yrSources & Verification
Every fact on this page is tied to a primary source below. Last fact-checked 2026-10-23.
- Colorado Sheep & Goat Hunting Brochure — Game Management Unit (GMU) Descriptions (pp. 16-17) — Colorado Parks and Wildlife · supports: GMU boundary description, Counties the unit lies in, Data analysis unit (DAU) the unit belongs to · accessed 2026-10-22
- 2023 Colorado Rocky Mountain bighorn sheep Harvest Estimates — Colorado Parks and Wildlife · supports: Percent success for bighorn sheep in unit S37, Hunters and harvest by weapon and season · accessed 2026-10-22
- CPW CPWAdminData feature service — GMU and sheep/goat unit boundaries — Colorado Parks and Wildlife GIS Unit · supports: Mapped extent of the unit, Which named ground falls inside the unit line · accessed 2026-10-22