Unit S57 (Big Thompson Canyon)

What CPW publishes for unit S57 is a boundary, not a bighorn sheep map. So the ground below is the unit's own and the read on where to start is ours, labelled as such. The unit lies in Larimer and Boulder counties.

The lines of the unit: Larimer CR 44H (Buckhorn Rd.), Stove Prairie Rd. (Larimer CR 27) and Larimer CRs 52E (Rist Canyon Rd.)

CPW has unit S57 bounded on the north by Larimer CR 44H (Buckhorn Rd.), Stove Prairie Rd. (Larimer CR 27), Larimer CRs 52E (Rist Canyon Rd.) and 54G; on the east by U.S. 287; on the south by Colo. 66 and U.S. 36; on the west by RMNP boundary, USFS trails 980 (Stormy Peaks Trail) and 928 (Signal Mountain Trail) and Pennock Creek-Elk Creek divide. Read it as a frame, not as a hint about animals. 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: Bulwark Ridge, Lookout Mountain and Crystal Mountain

Named high points inside the unit include Bulwark Ridge at 10,891 feet, Lookout Mountain at 10,593 feet, Crystal Mountain at 9,927 feet, Storm Mountain at 9,883 feet and Panorama Peak at 9,276 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: Piper Meadows, Rabbit Gulch and Estes Park

Below them sit Piper Meadows at 7,975 feet, Rabbit Gulch at 7,677 feet, Estes Park at 7,656 feet, Black Canyon at 7,616 feet and Emhaw Gulch at 7,473 feet. These are the folds worth watching, and the ones other hunters walk past on the way to somewhere steeper. Reaching the edge of one before light beats reaching its middle at noon.

Public ground to start from: Boedecker Reservoir SWA, Eagle Canyon STL and Lon Hagler SWA

CPW lists Boedecker Reservoir SWA, Eagle Canyon STL and Lon Hagler 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 75% 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 S57 is one piece of it. The rest of RBS-02 is unit S19 and unit S37. That matters twice over: the population objective and the licence numbers are set for the whole area, and the animals move across unit lines inside it without noticing them.

CPW's own harvest estimates put bighorn sheep success in unit S57 at 40% across all manners of take. That is an ordinary spread for this country, and it rewards whoever scouted. The plan: pick a glassing position across from the escape terrain and stay on it for hours, not minutes.

Glassing from Mount Olympus, Elk Ridge and Pole Hill

Take a position on one of Mount Olympus (8,775 ft), Elk Ridge (8,760 ft), Pole Hill (8,672 ft) and Mount Pisgah (8,596 ft) and be on it before light. Cold air slides downhill in the dark, so keep your scent out of the bowl you mean to watch; expect the thermals to turn uphill an hour after the sun reaches the slope. Give a basin forty minutes before you decide it is empty. On the rut hunts, late hunts put rams with ewe groups on the same rock.

Getting past the roads

There is little true four-wheel-drive road here, so distance from the gravel is the only thing separating you from the next hunter. 4 mapped public entry points fall inside the unit, so decide which one you take before the morning you take it.

Where unit S57 sits inside RBS-02

Across RBS-02, CPW's 2023 bighorn sheep success runs 100% in unit S19, 100% in unit S37 and 40% in unit S57. Unit S57 is the lowest of them, so whatever drives success in this herd is happening somewhere else in it. If the draw lets you choose, unit S19 carried the better number in the same herd — check its tag count before you read that as an easier hunt.

The way in: Larimer CR 44H, Larimer CR 27 and Larimer CRs 52E

We have no road inventory for this unit, so the only routes we can name are the ones CPW draws the boundary with: Larimer CR 44H, Larimer CR 27, Larimer CRs 52E, U.S. 287 and Colo. 66. Those are its edges, not its interior — useful because they are where you leave the pavement, and useless for telling you what the inside is like. Check each of them on a current motor-vehicle-use map before you count on it, because a line on a boundary description is not a promise of public access.

A first plan from the pins on this page

The map above marks Bulwark Ridge, Lookout Mountain, Storm Mountain and Panorama Peak as places to see from, and Donner Pass, Foggy Park, Nixon Park and Boedecker Reservoir SWA as ground to watch. Each pin is a named feature verified to fall inside the unit line, not a spot anyone has hunted. Walk between two of them rather than driving between four, and you will learn more in a day.

What a day here costs you

544 square miles is more country than a week will cover, so pick one drainage and learn it rather than driving the unit. The ground is gentle enough that the pack-out is a distance problem rather than a climbing one. Decide the night before where you will be at first light, and go there in the dark.

What we can't tell you

Some of the ground named above carries no land-status flag we trust, so check ownership on a current layer before you hunt it.