Colorado Unit S04 Bighorn Sheep Hunting Guide

Colorado Unit S04 is a limited-quota bighorn sheep unit tucked into some of the highest terrain in the state, with elevations ranging from 7,045 feet up to 13,786 feet across 181,785 total acres. For hunters chasing one of the most coveted tags in North American big game hunting, S04 represents a classic high-alpine sheep hunt: rugged, demanding, and available only through Colorado's draw system. This article breaks down what the data shows about this unit — harvest trends, tag structure, access, and trophy potential — so hunters can decide whether to put in for it.

Bighorn sheep tags are never easy to come by, and S04 is no exception. Every hunt here is limited-quota; there is no general season option for bighorn sheep in this unit. That means hunters are competing in Colorado's draw for a small handful of tags each year, and understanding the unit's terrain and hunt history matters before investing points or application cycles into it.

Unit Overview: Terrain and Access

S04 sits at serious elevation. With a floor of 7,045 feet and peaks reaching 13,786 feet, this is alpine sheep country — the kind of landscape where hunters need to be prepared for thin air, steep rock, and rapidly changing weather even in the warmer months. The 8,700-plus feet of elevation relief within the unit boundary means hunters could be glassing from timberline one day and working above treeline in true high-basin terrain the next.

Public land makes up 69% of the unit, giving hunters a solid base of accessible ground for scouting and hunting without needing to negotiate private land access for the majority of their hunt. Combined with the 23% wilderness designation within S04, a meaningful portion of this unit's public acreage falls under wilderness protections — meaning mechanized access (ATVs, e-bikes) is off the table in those areas, and hunters should expect foot or stock travel once they're inside the wilderness boundary. This is not a drive-to-your-spot unit in the core sheep habitat; expect to earn vertical feet on foot to reach bighorn terrain.

For nonresidents, it's worth noting that Colorado does not impose Wyoming's wilderness guide mandate — nonresidents can hunt the wilderness portion of S04 without being required to hire an outfitter. That said, given the technical nature of alpine sheep hunting and the percentage of wilderness ground in this unit, many hunters — resident and nonresident alike — still choose to bring in local knowledge or a guide given the difficulty of scouting rugged basin terrain from a distance.

Harvest Success Rates

The harvest data for S04 reflects what you'd expect from a well-managed, low-volume bighorn sheep unit: very small hunter numbers with generally high success.

• 2025: 3 hunters, 1 harvested — 33% success
• 2024: 4 hunters, 4 harvested — 100% success
• 2023: 5 hunters, 5 harvested — 100% success
• 2022: 5 hunters, 5 harvested — 100% success
• 2021: 5 hunters, 5 harvested — 100% success
• 2019: 5 hunters, 4 harvested — 80% success

Across five of the six years with recorded data, success sat at 80% or better, including four straight years of 100% success from 2021 through 2024. That's an exceptional track record for a species that is notoriously difficult to hunt even when tag odds are favorable. The 2025 dip to 33% (1 of 3 hunters) is a reminder that with such small sample sizes — just a handful of hunters per year — a single unsuccessful season can swing the percentage dramatically. Hunters shouldn't read too much into any single year's number in a unit this small; the more reliable signal is the multi-year run of near-universal success from 2021–2024.

What this tells hunters practically: if you draw a tag in S04, the historical odds strongly favor filling it, provided you put in the physical effort the terrain demands. Bighorn sheep hunts are rarely a numbers game in terms of hunter volume — they're an effort and terrain-knowledge game, and the data here suggests hunters who draw this tag have consistently gotten it done.

Trophy Quality

The counties overlapping Unit S04 carry a moderate history of trophy-class bighorn sheep records. This isn't a unit with a thin or absent trophy record, but it also isn't among the handful of units that dominate record-book lists year after year. Hunters should view S04 as a unit capable of producing a quality, mature ram, without the outsized trophy reputation of the state's top-tier sheep units.

It's worth remembering that trophy records are logged by county, not by hunt unit, so any historical entries associated with the counties overlapping S04 are shared with neighboring units in those same counties — the specific animals could have come from anywhere within that broader geographic area. Given the moderate designation here, hunters should set realistic expectations: this is a legitimate sheep hunt with a shot at a mature ram, but not a unit with the kind of concentrated, elite trophy pedigree that headlines the Colorado sheep draw conversation.

Tag Quota Trends

Colorado publishes separate tag quotas by hunt code, and S04's numbers are about as tight as it gets — which is standard for bighorn sheep management.

• S-F-S04-O2-R: 1 tag in 2024, rising to 2 tags in both 2025 and 2026 (stable at the higher level)
• S-M-S04-O1-R: 1 tag in 2024, 1 tag in 2025, increasing to 2 tags in 2026 — a 100% jump in that hunt code's quota
• S-M-S04-O2-R: Steady at 1 tag across 2024, 2025, and 2026

These are small, single-digit quotas across the board, which is typical of bighorn sheep management everywhere — herds are carefully managed, and tag numbers are conservative by design. The modest increases in two of the three hunt codes heading into 2026 suggest Colorado Parks and Wildlife sees some capacity to grow opportunity slightly in this unit, but hunters should not expect this to meaningfully change draw difficulty — these are still extremely limited tag pools. Each hunt code is managed independently, so a hunter interested in a specific sex or hunt option within S04 needs to track that code's own trend rather than assuming parity across the unit.

HuntPilot Analysis: Is S04 Worth Applying For?

Based on the data available through HuntPilot, Unit S04 is a legitimate, worthwhile bighorn sheep unit for hunters willing to commit to the long game of Colorado's sheep draw. Here's the honest breakdown:

The case for applying: Harvest success has been outstanding in four of the last five recorded years, with 100% success from 2021 through 2024. Public land access sits at a workable 69%, giving hunters room to scout and hunt public ground for the bulk of their season. The terrain — spanning more than 8,700 feet of elevation relief — offers the classic high-alpine sheep hunting experience that draws hunters to Colorado's mountain units in the first place. Tag quotas, while small, are trending flat to slightly up heading into 2026, which is a positive signal in a species where many units see quotas cut, not raised.

The case for caution: This is an extremely low-volume unit — quotas measured in single digits per hunt code mean this will be a long-odds draw for most applicants, particularly nonresidents. Trophy potential is described as moderate rather than exceptional, so hunters chasing a unit with a heavy record-book reputation may want to compare S04 against other Colorado sheep units with stronger trophy pedigrees. And while the 2021-2024 success rates are excellent, the 2025 drop to 33% is a reminder that these are small sample sizes where one or two unfilled tags swings the percentage hard — don't bank on guaranteed success without putting in the scouting and physical preparation a unit like this demands.

Bottom line: For a hunter with sheep points built up and realistic expectations about trophy class, S04 is a sound unit to have in the rotation. The access, terrain, and historical success rates all support it as a legitimate hunt — just go in treating the harvest numbers as a reflection of hunter effort and unit quality, not a guarantee.

How to Apply

Colorado bighorn sheep tags are allocated entirely through the state's limited-quota draw system — there is no general season or over-the-counter option for this species anywhere in the state, including Unit S04. Every hunt code in S04 (S-F-S04-O2-R, S-M-S04-O1-R, S-M-S04-O2-R) requires a successful draw before a hunter can pursue a bighorn ram or ewe here.

Colorado's sheep draw uses a preference point system, where points accumulate for hunters who apply but don't draw, improving long-run standing in the applicant pool. Both residents and nonresidents apply through the same statewide system, though nonresidents are typically capped at a share of available tags and often face a steeper point requirement than residents for the same hunt code. Because sheep tags are so limited across Colorado, most successful applicants — resident and nonresident alike — have accumulated points over multiple application cycles before drawing in units like S04.

Application dates, fees, and current draw odds for each hunt code in S04 change every cycle. For the most current numbers, hunters should check HuntPilot's Colorado state page at /states/CO or the live S04 unit page for up-to-date draw statistics before applying.

Frequently Asked Questions

What is the terrain like in Colorado Unit S04? S04 is high-alpine sheep country, with elevations ranging from 7,045 feet at the unit's lowest points to 13,786 feet at its highest peaks. That's more than 8,700 feet of vertical relief within the unit, meaning hunters can expect everything from lower-elevation approach terrain to true alpine basins and ridgelines above treeline. With 23% of the unit designated wilderness, a significant portion of the best sheep habitat requires foot or stock access rather than mechanized travel.

What is harvest success like in Unit S04? Harvest success has been strong overall, with 100% success recorded in 2021, 2022, 2023, and 2024, and 80% success in 2019. The 2025 season saw a dip to 33% success (1 of 3 hunters), which reflects the small hunter sample size typical of bighorn sheep units rather than a fundamental shift in herd quality or huntability. Hunters drawing a tag here have historically had very good odds of filling it.

How big are the bighorn rams in Unit S04? The counties overlapping S04 carry a moderate trophy history for bighorn sheep, meaning the unit has produced quality rams without being one of Colorado's standout trophy destinations. Hunters should expect a solid, mature-ram opportunity rather than guaranteed record-book potential, and should understand that trophy records are attributed at the county level and shared with neighboring units in the same counties.

Is Colorado Unit S04 worth applying for? Yes, for hunters prepared for a demanding alpine hunt and realistic about trophy expectations. The combination of strong historical harvest success, 69% public land, and stable-to-increasing tag quotas heading into 2026 make it a reasonable unit to target in the Colorado sheep draw, particularly for hunters who have been building points and want a unit with a solid — if not elite — track record.

Is Unit S04 a good option for nonresident hunters? Nonresidents can apply for and hunt S04, and Colorado does not require a guide for nonresidents hunting wilderness areas the way Wyoming does. However, given the technical alpine terrain, the 23% wilderness component, and the overall difficulty of sheep hunting, many nonresidents — and plenty of residents — opt to use local guides or spend significant time scouting before the season to maximize their chances in this demanding unit.