Hogback Mountain Lookout via Nelson, Montana | Trail Guide

MONTANA 4x4 TRAIL GUIDE · MT-0017

Hogback Mountain Lookout via Nelson

FSR 4155 · FSR 298-B1 · Big Belt Mountains · York–Nelson area, Montana

4/10AGF Difficulty · Moderate · set for the 2025 loop; under review

5.36 MIOne way on FS roads; 10.7 round trip (MVUM)

CLOSED OCT 15–MAY 15FSR 4155 MP 0.786–4.482 and 298-B1 (MVUM)

USFSHelena Ranger District

THE 2025 RELIC RUN LOOP IS NOT PUBLISHED. DO NOT ATTEMPT IT. AGF's 2025 Relic Run loop (Avalanche Gulch → Magpie → an "Antelope Creek" connector → Grouse Ridge → Hogback → Nelson) is NOT published. About 3 miles of that line has no designated Forest Service road or trail and crosses land that Forest Service ownership data classifies as non-Forest Service and BLM land data classifies as private. The lower Avalanche Gulch road runs on a Forest Service easement that a mining-claim owner is reportedly challenging in court (Hunt Talk forum, April 2026, secondary). This page covers only the designated Nelson-side road to the lookout.

SEASONAL: THE CLIMB FROM NELSON IS OPEN TO MOTOR VEHICLES ONLY MAY 16–OCT. 14. FSR 4155 MP 0.786–4.482 and FSR 298-B1 are open May 16–Oct. 14 and closed Oct. 15–May 15 (MVUM). For 2026, the closure began Oct. 15, 2026 and runs to May 15, 2027 (MVUM dates repeat yearly unless the MVUM changes). FSR 4155 MP 0–0.786 is open May 16–Dec. 1. After Oct. 15 the lookout can be reached only by the yearlong FSR 138 → FSR 298 approach, snow permitting; its mileage was not measured, and this guide does not cover it. Highway-legal vehicles only: the MVUM designates every Hogback-side road for highway-legal vehicles only. Non-street-legal ATVs, UTVs and OHVs are not allowed. Private parcels may lie around Nelson and along York-Nelson Rd (AGF research; not confirmed): respect all posted signs and gates. The 2024 Horse Gulch Fire burn scar is in the area: expect hazard trees, washouts and flash-flood risk. The Helena-Lewis and Clark warned on Dec. 17, 2025 of numerous trees down across roads and trails after a windstorm: carry a saw. Snow is possible at high elevation by mid-October: a participant in the 2025 Relic Run guessed there might be leftover snow "up high and north facing" the week before the Oct. 19 run (IH8MUD forum, secondary). Check the current MVUM and land-manager rules before you go: official closures, posted signs and private property override this guide. Call the Helena Ranger District (406-449-5201) before you go, and read Know Before You Go.

AGF HAS NOT CONFIRMED DRIVING THIS ROAD. AGF's Oct. 19, 2025 Relic Run was in this area, but the club rerouted on Oct. 9, 2025 "to avoid a seasonal closure happening next week" (IH8MUD forum, secondary), most likely this road's Oct. 15 closure, and no GPS track from the run was recovered. Which roads the run actually drove is unconfirmed. This guide is built from the Forest Service MVUM and clearly labeled secondary sources.

WHAT THIS GUIDE COVERS

FSR 4155 and 298-B1 to the Lookout

From FSR 4155 MP 0 at the end of the county York-Nelson Rd: FSR 4155 "Cottonwood Gulch - Powerline" for 4.482 miles, then FSR 298-B1 "Hogback Extension" for 0.874 mile, to the west end of FSR 298 "Hogback Mountain" at the lookout area. That is 5.36 miles one way and 10.7 miles round trip, returning the same way (FS MVUM data).

NOT INCLUDED: the 2025 Relic Run loop and everything east of the lookout on it (Avalanche Gulch FSR 359, Magpie FSR 425, the "Antelope Creek" connector, Grouse Ridge FSR 4118 and 4118-C1), the FSR 298 → FSR 138 return (mileage not measured), Jimtown Rd, and the county York-Nelson Rd approach.

WHY 4/10

Moderate · Rating Under Review

AGF has not re-rated this road for this scope. The 4/10 and the terrain scores below were set for the full 34.5-mile 2025 loop, whose rating notes cite ruts, mud, exposed two-track, brush and recovery potential (AGF record). The one located hard spot, a mud recovery of two full-size trucks on Jimtown Rd (2025 trip report, IH8MUD forum, secondary), is outside this guide. No source places the loop's hardest obstacle on FSR 4155 or 298-B1. The Forest Service lists FSR 4155 and 298-B1 at maintenance level 2, "High Clearance Vehicles," native surface, "Not Maintained for Passenger Car" (FS EDW, queried Oct. 9, 2026); that is a maintenance standard, not a condition report. Treat 4/10 as provisional for this road: verify. Snow, mud, deadfall and fire are condition changes, not part of the rating.

Rock

2/5

Mud

3/5

Water

1/5

Exposure

3/5

Snow

4/5

Pinstriping

3/5

Snow, mud, runoff, deadfall and fire are condition changes, not part of the base rating.

ROUTE & MAP

Getting There

From Helena, take York Rd to York, then the county York-Nelson Rd (7.3 miles of gravel, Lewis and Clark County) toward Nelson (AGF research; verify). FSR 4155 begins at 46.7967, -111.7951. Climb FSR 4155 for 4.48 miles to its end, then turn east on FSR 298-B1 for 0.87 mile to the west end of FSR 298 at the lookout area. Return the same way.

LOADING MAP…

Helena-Lewis and Clark alerts →Big Belts MVUM (PDF) →ROUTE FILE: not published yet

The pin marks the Hogback lookout area at the west end of FSR 298 (Forest Service EDW MVUM endpoint coordinate). The route starts at FSR 4155 MP 0 (46.7967, -111.7951). No downloadable track is published, and no GPS track from the 2025 run was recovered.

VEHICLE FIT

Rig Requirements

Stock 4x4: Yes
High clearance: Recommended (FS: maintenance level 2, high-clearance road)
Tires: 31-inch minimum
Rear locker: No
Front locker: No
Winch: Recommended
Full-size: Yes, street-legal only (highway-legal MVUM roads)
Body damage: Moderate risk

Rig requirements below, except the Full-size row, were set for the full 2025 loop and are under review for this road. A street-legal stock 4x4 with good all-terrain tires (AGF record). Carry a full-size spare, radio, saw, recovery gear, extra water and fuel, and offline maps. Use rated recovery gear only: the 2025 trip report recorded a failed ratchet strap (IH8MUD forum, secondary). Non-street-legal OHVs and UTVs are not allowed on these roads (MVUM).

TRIP PLANNING

Know Before You Go

Season: May 16–Oct. 14 for FSR 4155 MP 0.786–4.482 and 298-B1; FSR 4155 MP 0–0.786 May 16–Dec. 1 (MVUM)
Typical trip: Verify (10.7 mi round trip on FS roads plus the approach)
Vehicles: Highway-legal only (MVUM)
Camping: Dispersed-camping corridors not confirmed: check the MVUM
Trailer parking: Verify
Turnaround: Limited (AGF record)

Hunting season: Montana's general deer and elk season runs Oct. 24–Nov. 29, 2026 (FWP). Expect hunters, camps and parked vehicles; wear blaze orange outside the vehicle. Archery season runs to Oct. 18. A youth deer hunt runs Oct. 15–16 (FWP).
The Helena-Lewis and Clark alerts page says "food storage orders are in effect on the Helena-Lewis and Clark National Forest" (R1-2023-02, NCDE-focused); whether it covers the Big Belts: verify. Store food bear-safe regardless.
No Helena-Lewis and Clark alert listed a Big Belts closure on Oct. 9, 2026 (fire danger Moderate). The 2024 Horse Gulch Fire area closure was scheduled to end May 15, 2025 and is no longer listed.
Contacts: Helena Ranger District 406-449-5201; Lewis and Clark County Public Works 406-447-1631 for York-Nelson Rd; Townsend Ranger District 406-266-3425 for the Avalanche Gulch side.

SOURCES

Sources & Review

USFS EDW MVUM roads layer (queried Oct. 9, 2026) (FSR 4155, 298-B1, 298, 138, 4118, 359, 425: classes, dates, miles, endpoints; ML2 high clearance, native surface on 4155 and 298-B1)
USFS EDW MVUM trails layer (no motorized trail in the Magpie–Grouse Ridge gap)
USFS EDW RoadBasic inventory (no FS road in the gap)
USFS EDW Basic Ownership (non-FS land in the gap; FS land at FSR 4155 MP 0)
BLM National SMA (limited scale) (private land in the gap and on lower Avalanche Gulch)
MVUM: Helena-Lewis and Clark NF, Big Belt Mountains (April 2023) (official map; read by text extraction only)
Lewis and Clark County: County Maintained Roads (York Nelson gravel 7.3 mi; 406-447-1631)
Helena-Lewis and Clark NF: Offices (Helena RD 406-449-5201; Townsend RD 406-266-3425)
Helena-Lewis and Clark NF alerts (checked Oct. 9, 2026; no Big Belts closure; Dec. 2025 windstorm advisory)
Helena-Lewis and Clark NF: Horse Gulch area closure (historical; Aug. 30, 2024–May 15, 2025)
InciWeb: Horse Gulch Fire update (July 20, 2024) (historical; fire 5 mi south of York)
Hunt Talk: Avalanche Gulch - Access at risk (April 2026) (secondary forum; easement reportedly disputed in court; no case number)
PLWA: Avalanche Gulch (secondary (access advocacy group); private land and a 30-ft FS road easement on lower Avalanche Gulch)
IH8MUD: 2025 Relic Run (page 2) (secondary forum; Oct. 9, 2025 reroute to avoid a seasonal closure)
IH8MUD: 2025 Relic Run (page 3) (secondary forum; trip report, Jimtown Rd mud recovery, snow concerns)
Montana FWP: Hunting seasons (2026 deer/elk archery Sept. 5–Oct. 18; youth deer Oct. 15–16; general Oct. 24–Nov. 29)

Last reviewed Oct. 9, 2026. No closure is listed, but FSR 4155 MP 0.786–4.482 and 298-B1 close to motor vehicles Oct. 15–May 15, the roads are highway-legal only, the 2025 Relic Run loop is not published, and the 4/10 is under review for this scope. AGF has not confirmed driving this road.

AGF ratings describe normal, dry-condition difficulty. They do not mean a route is legal, open or passable today. Spot something out of date? Use the Contact page.