280 Forest Service, 39 BLM, 7 Army Corps and 3 National Park Service. 220 can be booked ahead
Suspension for long, slow, loaded dirt
The work here is hours of rough one-lane road at low speed with a full load, not rock crawling. The Forest Service expects 12 to 15 miles per hour on the 101-mile Magruder Road Corridor and 10 to 15 on the 53-mile Elk City Wagon Road, which is four to six hours of washboard, switchbacks and rock.
That favors spring rates chosen for the real finished weight and damping that survives a long descent without fading. Tell the shop the byways as well as the dirt: the same vehicle will do 162 miles of pavement on the Salmon River byway to reach the start.
A suspension shop matches spring rates and shock valving to the vehicle's real loaded weight, corrects the geometry that a lift changes, and aligns it afterward. On an overland vehicle the goal is control and durability under constant load, not maximum height.
The work usually includes
01Coil and leaf springs rated for the load
02Shocks: monotube, remote reservoir or adjustable
03Control arms, track bars, driveline and brake line corrections
04Air bags or helper springs for heavy rear loads
05Alignment after the work
06Advice on gearing when tire size goes up
How to choose a suspension shop
The right shop asks about weight before it asks about height.
01Weigh the vehicle loaded, or ask the shop to. Choosing springs without a weight is a guess.
02Ask what else the lift changes on your platform: alignment range, driveline angles, brake lines, headlight aim and driver-assistance sensors.
03Ask whether they align in house.
04Ask for the least height that clears your tires and keeps the geometry happy. More lift is not better.
05Ask how it will ride at both ends of your use: empty around town and loaded on washboard.
What to have ready before you ask for a quote
Weight is the number that matters.
01Year, model and drivetrain
02Current tire size and the size you want to run
03Everything bolted on: bumper, winch, rack, tent, drawers, water
04Loaded weight, if you have been across a scale
05How you use it, and a budget range
Questions people ask
How much lift do I need?
Less than you think. Most overland travel is dirt roads, washboard and the occasional ledge, and the vehicle spends its life loaded. Enough lift to clear a sensible all-terrain tire, with springs rated for your weight, usually drives better and breaks less than a tall kit.
Why does my truck sag in the back?
Because the factory springs were chosen for an empty truck. Drawers, a fridge, water, a tent and a rear bumper add constant weight. The fix is springs rated for that constant load, sometimes with air bags for the occasional heavy trip.
Do bigger tires mean I need new gears?
Larger tires make the engine and transmission work harder and change the speedometer reading. Whether re-gearing is worth it depends on the tire size, the vehicle and how much weight you carry. A shop that knows your platform can tell you where the line is.
How high is Idaho?
From Lewiston at 740 feet to Borah Peak at 12,662.
Altitude decides what your engine, your brakes and your lungs have to work with, and how late in the year the passes open.
02,0004,0006,0008,00010,00012,000
Feet above sea level
Towns
StanleyWhere State Highway 21 meets State Highway 75 in the Sawtooth Valley. The Salmon River and Ponderosa Pine scenic byways both start here, and the Custer Motorway leaves Highway 75 eleven miles east.6,260 ft
KetchumOn State Highway 75 at the south end of the Sawtooth National Recreation Area. The Sawtooth Scenic Byway climbs north from here to Galena Summit.5,844 ft
ArcoWhere US 20, US 26 and US 93 meet. The gateway town for Craters of the Moon National Monument and Preserve and its Loop Road.5,325 ft
ChallisOn the Salmon River Scenic Byway. BLM field office, and the north end of the Custer Motorway past the Land of the Yankee Fork interpretive center.5,246 ft
McCallOn Payette Lake north of Boise, in the Payette National Forest, which reaches east to the Frank Church-River of No Return.5,013 ft
Elk CityEnd of State Highway 14 and of the Elk City Wagon Road. The Forest Service calls it a small, full-service community with fuel; the Magruder corridor starts past Red River.4,011 ft
SalmonHeadquarters of the Salmon-Challis National Forest and a BLM field office. The BLM calls it a full-service community, and the Lewis and Clark Back Country Byway starts at Tendoy, 19 miles south.3,941 ft
Twin FallsOn I-84 above the Snake River canyon. BLM district office, with the Jarbidge Field Office, for the desert south of the highway.3,733 ft
GrangevilleOn US 95 at the edge of the Camas Prairie. State Highway 14 runs east from here toward Elk City and the west end of the Magruder Road Corridor.3,398 ft
BoiseState capital on I-84. BLM Idaho state office and Boise District, with the Four Rivers and Bruneau field offices. State Highway 21, the Ponderosa Pine Scenic Byway, runs from here to Stanley.2,700 ft
MarsingOn the Snake River southwest of Boise. The BLM’s Owyhee Field Office, which looks after the Owyhee Uplands Back Country Byway, is in town.2,297 ft
Coeur d’AleneOn I-90 in the Panhandle. BLM district and field office, and the service town for the Idaho Panhandle National Forests.2,192 ft
SandpointWhere US 95 meets US 2 north of Lake Pend Oreille. Endowment land north of the lake carries a grizzly bear food storage requirement.2,101 ft
RigginsOn US 95 where the Little Salmon meets the Salmon River, between the Payette and Nez Perce-Clearwater national forests and below the Hells Canyon rim.1,806 ft
KamiahOn US 12 beside the Clearwater River. Supervisor’s office for the Nez Perce-Clearwater National Forests and the western approach to the Lolo Motorway.1,239 ft
LewistonWhere US 12 meets US 95 on the Snake River, close to the state’s low point of 710 feet. West end of the Northwest Passage Scenic Byway and a base for Hells Canyon.740 ft
Passes, high roads and summits
Borah PeakThe highest point in Idaho, in Custer County. No road to the top12,662 ft
Galena SummitSawtooth Scenic Byway: Shoshone north through Ketchum to the Sawtooth Valley8,701 ft
Magruder Road CorridorRed River, east of Elk City, to Darby, Montana7,920 ft
Lemhi PassLewis and Clark Back Country Byway and Adventure Road: A loop from Tendoy on State Highway 28, 19 miles south of Salmon7,368 ft
Willow Creek SummitUS 93 between Mackay and Challis, below the west face of Borah Peak7,165 ft
Banner SummitPonderosa Pine Scenic Byway: Stanley to Boise on State Highway 217,056 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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