273 Forest Service, 15 BLM and 15 National Park Service. 231 take reservations
The coldest reading on record in the contiguous United States 7
-70°F
Rogers Pass, 40 miles northwest of Helena, January 20, 1954
The vehicle length limit on Going-to-the-Sun Road 25
21 ft
Between Avalanche Creek and Rising Sun, with a width limit of 8 feet including mirrors
Tires for clay, gravel and a Montana winter
The problem here is not sharp rock so much as wet clay. The BLM says many roads in the Upper Missouri River Breaks cross soils that become absolutely impassable when wet, and the Fish and Wildlife Service says most refuge trails are impassable in wet weather. That argues for a tread that clears itself and for airing down properly rather than for the most aggressive compound.
Winter is a legal question too. Studded tires are legal from October 1 to May 31, and the state can require chains in designated areas at any time of year. Carry a full-size spare, as the Forest Service tells Magruder drivers to.
Tires are the only part of the vehicle that touches the ground, and on a loaded rig they work close to their limits. A good tire shop starts with load rating and size, then tread. It will also tell you when the tire you want will rub, need different wheels or throw off your gearing.
Expect help with
01Choosing a tire by load, terrain and season
02Wheels with the right offset and load rating
03Mounting, balancing and tire pressure sensors
04A matching full-size spare
05Alignment, rotation and repairs
How to choose tires for overland travel
Tread pattern is the last decision, not the first.
01Match the load rating to your real axle weights, not to the badge on the fender.
02All-terrain tires suit most overland travel. Mud-terrains are louder, heavier and wear faster, and earn it only in real mud and rock.
03Buy five. A matching full-size spare that you rotate in is worth the money when the nearest tire shop is a day away.
04Check the wheels too. Wheels have load ratings, and the wrong offset stresses bearings and rubs.
05Ask whether the shop can move or reprogram your tire pressure sensors.
What to have ready before you ask for a quote
A tire quote is quick when the shop knows what the tire has to carry.
01Vehicle, current tire size and wheel size
02Lift height, if any
03Loaded weight, or a list of what is on the vehicle
04Where you drive most: pavement, gravel, rock, sand, snow
05A budget range for five tires
Questions people ask
What does load range mean?
It describes how much weight a tire can carry at a given pressure. Heavier builds, vans and truck campers usually need a higher load range than the vehicle came with. The tire's sidewall and the placard in the door jamb are the places to start, and a tire shop can work through the numbers with you.
How big can I go?
Every platform has a size that fits at stock height, a size that fits with a modest lift, and a size that needs trimming and gears. Tell the shop your lift and wheels and ask what fits without rubbing at full steering lock and full compression.
Should I air down?
On washboard, sand and rock, lower pressure gives a better ride and more traction and is easier on the vehicle. It also means you need a way to air back up before pavement. How low depends on your tire, your weight and your speed, so ask your tire shop and start conservatively.
How high is Montana?
From Libby at 2,097 feet to Granite Peak at 12,799.
Altitude decides what your engine, your brakes and your lungs have to work with, and how late in the year the passes open.
2,0004,0006,0008,00010,00012,00014,000
Feet above sea level
Towns
Red LodgeWhere the Beartooth Highway starts its climb on US 212, heading for Beartooth Pass and Cooke City.5,568 ft
ButteOn I-90 with the BLM’s Western Montana District office. The Pipestone off-highway vehicle area is about 15 miles east at exit 241.5,535 ft
PhilipsburgIn Granite County, on the far side of Skalkaho Pass from the Bitterroot Valley. Montana 38 over the pass closes for the winter.5,243 ft
DillonHome of the BLM field office that manages more than 900,000 acres in Beaverhead and Madison counties, and the Big Sheep Creek byway to the south.5,097 ft
EnnisOn Montana 287. The Forest Service routes Gravelly Range traffic from here by the Varney road and the Call road, and keeps the area’s maps at its office in town.4,946 ft
BozemanOn I-90. The Custer Gallatin’s Bozeman Ranger District is one of the five west-side districts under the forest’s food storage order.4,811 ft
HelenaState capital, and half the name of the 2.8-million-acre Helena-Lewis and Clark National Forest. Rogers Pass, 40 miles northwest, holds the national cold record.4,048 ft
LewistownBLM field office for the Upper Missouri River Breaks and seat of the North Central Montana District. One of the two offices the BLM names for byway conditions.3,952 ft
DarbyThe Montana end of the Magruder Road Corridor. The Forest Service counts eight to ten hours from Red River, Idaho, to Darby without rest stops.3,884 ft
HamiltonIn the Bitterroot Valley on US 93, near the west end of Montana 38 and in the middle of the 1.6-million-acre Bitterroot National Forest.3,570 ft
WinifredOne end of the Missouri Breaks byway, which the BLM runs between here and the James Kipp Recreation Area on US 191.3,228 ft
MissoulaOn I-90 beside the 2.3-million-acre Lolo National Forest. The BLM field office here manages the Garnet Back Country Byway, which leaves Montana 200 about 30 miles east.3,208 ft
BillingsOn I-90 in south-central Montana. The BLM’s Montana/Dakotas State Office is here.3,122 ft
KalispellIn the Flathead Valley below the 2.4-million-acre Flathead National Forest, west of Glacier National Park.2,955 ft
Fort BentonWhere the Breaks begin on US 87. The Missouri Breaks Interpretive Center here holds maps and road conditions for the monument.2,635 ft
LibbyOn the Kootenai River. The 67-mile Lake Koocanusa Scenic Byway runs north from here to Eureka on Highway 37.2,097 ft
Passes, high roads and summits
Granite PeakThe highest point in Montana, in Park County. No road to the top12,799 ft
Beartooth PassBeartooth Highway (US 212): Red Lodge to Cooke City, by way of the northwest corner of Wyoming10,947 ft
Mount ClevelandThe highest peak in Glacier National Park, by the park’s own figure10,448 ft
Crystal ParkPioneer Mountains Scenic Byway: Montana Highway 484 at Wise River south to County Highway 2787,800 ft
Skalkaho PassSkalkaho Highway (Montana 38): Ravalli and Granite counties, across Skalkaho Pass7,261 ft
Logan PassGoing-to-the-Sun Road: The west entrance of Glacier National Park to the east entrance, over Logan Pass6,646 ft
Nez Perce PassMagruder Road Corridor: Darby, Montana, to Red River, Idaho, between the Selway-Bitterroot and Frank Church wildernesses6,598 ft
Pass, road and summit elevations are the figures published by the agency that manages them. Town elevations are the town’s or county’s own
figure where it publishes an exact one; the rest are from the U.S. Geological Survey (3D Elevation Program at the place’s official coordinates),
retrieved September 18, 2026. Every source is listed at the foot of the page.
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