Montana Bighorn Sheep

Unit S423 (Gibson Lake North)

Montana Hunting Guide — Bighorn Sheep

Unit S423 lies in Teton County. Montana FWP publishes no per-unit bighorn sheep success figure we can verify for this unit. Check land status on a current map before you plan a route.

View Draw Odds Montana Hunting Guide

Build your own PDF hunt guide for Unit S423

Answer a few questions about your tag, your season and your rig, and the Field Intelligence Report builds a print-ready Montana Unit S423 guide around your hunt: three ranked spots with morning, afternoon and evening plays, a day-by-day plan, topo maps with every pin numbered, a camp and access plan, the legal and retrieval rules for this unit, shot discipline, a meat-care and pack-out plan, and a pre-trip checklist. Every coordinate sits on land recorded as public.

Bighorn Sheep guide

Free accounts get one report a year with the top spot unlocked. ProHunt Pro includes unlimited reports, all three spots, the full camp plan, and GPX/KML downloads for onX and Google Earth. Prefer to see one first? Open the builder and pick any unit.

Bighorn Sheep Hunting in Unit S423

Unit S423 lies in Teton County. Montana FWP publishes no per-unit bighorn sheep success figure we can verify for this unit. Check land status on a current map before you plan a route.

Where to Find Bighorn Sheep in Unit S423

Montana FWP's material on unit S423 stops at the boundary — there is no agency account of where its bighorn sheep live. Every place named below sits inside the unit line. Which of them holds animals in your season is for you to find out. The unit lies in Teton County.

The lines of the unit: Sun River, Sun Canyon and Blacktail Gulch

Montana FWP draws unit S423 in Teton County with a boundary that runs on USFS Trail 223 and USFS Trail 128, and on Sun River, Sun Canyon, Blacktail Gulch and Erosion Creek, walked corner by corner in its hunting district legal descriptions. 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: Arsenic Mountain, Sheep Reef and Horse Hill

Named high points inside the unit include Arsenic Mountain at 8,476 feet, Sheep Reef at 6,439 feet, Horse Hill at 5,725 feet, Elk Hill at 5,613 feet and Sulphur Hill at 5,604 feet. Several carry a public-land flag in our data, which makes them the first places to try for a view. Sheep on lower country still need rock, and on a desert unit the rock is the whole hunt.

Holding ground: Two Shacks Flat, Reclamation Flats and Big George Gulch

Below them sit Two Shacks Flat at 5,060 feet, Reclamation Flats at 4,745 feet, Big George Gulch at 4,737 feet, Mortimer Gulch at 4,733 feet and Blacktail Gulch at 4,554 feet. These are the folds worth watching, and the ones other hunters walk past on the way to somewhere steeper. Pick the one with the least road on its upwind side.

Water: Scattering Springs

Named sources include Scattering Springs. Nothing in the data says which of them run in autumn, so a scouting trip earns its fuel.

Unit S423 terrain and land status

Measured from the unit boundary, not from the agency write-up

Named features inside the unit

Glass from: Arsenic Mountain (8,476 ft), Sheep Reef (6,439 ft), Horse Hill (5,725 ft)

Holding ground: Two Shacks Flat (5,060 ft), Reclamation Flats (4,745 ft), Mortimer Gulch (4,733 ft), Scattering Springs

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 S423

Montana FWP publishes no bighorn sheep success figure for unit S423 that we can tie to this unit alone, so we won't quote one. The plan: pick a glassing position across from the escape terrain and stay on it for hours, not minutes.

Glassing from Horse Hill, Elk Hill and Sulphur Hill

Take a position on one of Horse Hill (5,725 ft), Elk Hill (5,613 ft), Sulphur Hill (5,604 ft) and Mule Hill (5,440 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. Glass the edges first, then the shaded timber, then the edges again as the light goes. On the rut hunts, late hunts put rams with ewe groups on the same rock.

The way in: USFS Trail 223 and USFS Trail 128

We have no road inventory for this unit, so the only routes we can name are the ones Montana FWP draws the boundary with: USFS Trail 223 and USFS Trail 128. 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. Park on the boundary and walk; a unit you can only enter from its rim rewards whoever is willing to leave the truck at the rim.

A first plan from the pins on this page

The map above marks Arsenic Mountain, Sheep Reef and Horse Hill as places to see from, and Two Shacks Flat, Reclamation Flats, Mortimer Gulch and Scattering Springs as ground to watch. Each pin is a named feature verified to fall inside the unit line, not a spot anyone has hunted. Join two of them into a morning: be on the first before light, move to the second once the thermals turn.

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. We have no bighorn sheep success figure for this unit that survives checking against Montana FWP's own harvest and hunter counts, and we would rather say so than print a statewide average as though it were measured here.

Montana rules that decide your day

Summarised from FWP regulations. They change — read the current regulations and your permit-tag before you hunt.

Legal shooting hours

Big game may be taken from half an hour before sunrise to half an hour after sunset.

Motorized retrieval

Montana has no general off-road retrieval allowance; travel stays on open routes.

Tagging

Validate the tag and attach it to the carcass before moving the animal.

Leaving meat

Wasting game meat is illegal.

Where you may not shoot

Occupied structures — No discharging a firearm within 150 yards of an occupied dwelling without permission, and no shooting from or across a public road.

Bighorn Sheep: where to put the shot

Broadside or quartering away, on the back edge of the front leg about a third of the way up the body.

Shots to refuse

Nothing behind or overlapping the animal you picked.
Your maximum range is the farthest you have shot a three-shot group into a paper plate from the rest you are carrying.
Pass the shot you are talking yourself into.

Plan the carry: roughly 40– 120 lb of boned-out meat, before head and hide — two large coolers. ProHunt planning estimate, not an agency figure.

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Bighorn Sheep Success Rates

Montana FWP's 2023 harvest estimates carry no bighorn sheep row for unit S423 that we can read back to this unit on its own. Where the agency reports a unit inside a grouping, or prints a table our parser cannot resolve to a single column, we leave the number out rather than publish a statewide average as though it had been measured here. Montana FWP's current harvest estimates are the place to check before you apply.

Bighorn Sheep Draw Odds

Season	Tags	Applicants	Draw %	Pts (n/p)
Rifle — General either sex (resident)	2	344	0.6%	—

Data from 2025 draw results. Each row is one residency pool — read the label before the number. This agency publishes no point thresholds, so the Pts column stays blank and these are pool odds, not what a point total draws.

Open in Draw Odds Engine

Montana FWP's draw recap has no bighorn sheep record we can tie to unit S423. That usually means the licence is sold over the counter, is issued under a hunt code covering several units, or was not offered in the years we hold. Rather than estimate a point requirement, we leave it blank — check Montana FWP's own draw recap for the hunt code you mean to apply for.

Unit Logistics & Expectations

Planning Notes

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Road Conditions

Paved highway to gateway areas, then gravel and USFS two-track. 4WD strongly recommended for upper access. Early snow closes higher roads.

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Hunting Pressure

Minimal during the season. Scouting pressure by other applicants and outfitters is common in summer.

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Weather

Sheep seasons span warm September weather through cold late-fall conditions with snow potential. Pack layered systems.

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Permit Notes

All licenses are issued through FWP's sheep special drawing. Confirm the current permit code and apply before deadlines.

Note: Consider hiring a local guide for the scouting phase — ground intel is invaluable for a once-in-a-lifetime tag.

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Frequently Asked Questions

Where is Colorado unit S423?

Unit S423 lies in Teton County. Montana FWP draws unit S423 with a boundary that runs on USFS Trail 223 and USFS Trail 128, and on Sun River, Sun Canyon, Blacktail Gulch and Erosion Creek, walked corner by corner in its hunting district legal descriptions.

What is the bighorn sheep success rate in unit S423?

Montana FWP publishes no bighorn sheep success figure we can tie to unit S423 on its own — the 2023 harvest tables either omit the unit or report it in a grouping we could not read back to it reliably. Rather than quote a statewide average as though it were measured here, we say so. Check Montana FWP's current harvest estimates before you apply.

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Sources & Verification

Every fact on this page is tied to a primary source below. Last fact-checked 2026-10-24.

Montana FWP Hunting District Legal Descriptions, 2026/2027 — sheep hunting districts (pp. 10-13) — Montana Fish, Wildlife & Parks · supports: GMU boundary description, Counties the unit lies in · accessed 2026-10-24
FWP hunting district feature services — deer/elk, antelope, moose, bighorn sheep and mountain goat districts (2026 and 2027 seasons) — Montana Fish, Wildlife & Parks · supports: Mapped extent of the unit, Which named ground falls inside the unit line · accessed 2026-10-24