RV travel in Idaho
Idaho is a quietly excellent RV state that gets overlooked between Yellowstone next door and the Cascades to the west. The Sawtooths, Hells Canyon, the Lochsa River corridor on US-12, and the Snake River Plain together cover everything from alpine to high desert in a long week. Distances between fuel are real -- the Lemhi and Clearwater corridors can run 60-80 miles between pumps -- and the panhandle gets serious winter from November through April. Plan around the snow and the short shoulder season and Idaho rewards you with empty National Forest roads, very cheap state-park camping, and almost no traffic.
Last verified: 14 May 2026
Free RV PDF guide to Idaho
Driving rules, RV-friendly and RV-restricted highways, NPS reservation rules, BLM and NF boondocking, propane, dump stations, weather, and emergency contacts. Save it to your phone for offline use on the road.
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Driving rules
Interstate (cars)80 mph (rural stretches; 75 mph elsewhere)
Interstate (trucks + towing)70 mph
US/State highway (cars)70 mph
US/State highway (towing)65 mph
Built-up areas25-35 mph (posted)
Drive onRight
RV passenger seatbeltsRequired for front-seat occupants; under-18s in all seats
Cell phone use while drivingHands-free only; hand-held banned statewide since 2020
RV-friendly and RV-restricted highways
RV-friendly
I-84Main east-west corridor through Boise and the Snake River Plain. Easy big-rig grades; Pendleton-side climbs are in Oregon.
I-86 / I-15Pocatello to Idaho Falls and on to Montana. Wind exposure on I-15 north of Idaho Falls.
I-90Coeur d'Alene to the Montana line over Lookout Pass. Chains/M+S required Oct-Apr if posted.
US-95The state's only continuous north-south route. White Bird Hill (US-95 south of Grangeville) is a 7% sustained grade with sharp curves -- doable in any rig but use low gears.
US-20 / US-26Idaho Falls to West Yellowstone and through Craters of the Moon. Big rigs fine; high elevation means slow climbs out of Mackay.
US-93Twin Falls to Salmon via the Lost River valley. Long fuel gaps; gorgeous.
RV-restricted
US-12 (Lochsa Highway, Lolo Pass area)Two-lane, narrow shoulders, tight curves through old-growth corridor. Megaload-restricted historically; rigs over 40 ft are legal but tough. No truck stops between Kooskia and Lolo (100+ miles).
ID-21 (Banner Summit / Lowman to Stanley)Steep grades and tight switchbacks above Lowman. Closed at avalanche zones some winters.
ID-75 (Galena Summit)Open year-round but plowed-narrow in winter. Trailers over 35 ft tough on the switchbacks.
Magruder Corridor (FR 468)Unpaved primitive road across the Bitterroots. Don't even think about it in a fifth wheel.
National parks and monuments
Yellowstone NP (West Entrance via Idaho)$35/vehicle (7 days), $80 America the Beautiful annual. All Yellowstone campgrounds reservable via recreation.gov; book 6+ months ahead. Idaho-side access via US-20 from Idaho Falls -- 110 miles.
Craters of the Moon NM & Preserve$20/vehicle (7 days). Lava Flow Campground first-come, no hookups, RVs to 35 ft. Volcanic dust is fierce; close vents on arrival.
City of Rocks National ReserveFree entry; camping $13-23/night. campgrounds reservable via reserveamerica.com (Idaho state-park system manages). Many sites tight for big rigs -- check site lengths.
Nez Perce NHP (multiple sites)Free entry. Visitor center near Spalding; no camping on park property. Use Winchester Lake State Park or Hells Gate State Park.
Hagerman Fossil Beds NMFree entry. Day-use only; no camping. Three Island Crossing State Park nearby for RVs.
Minidoka NHSFree entry. Day-use historic site (WWII Japanese internment camp); no camping.
Boondocking and dispersed camping
BLM: Idaho BLM lands cover the Owyhee Canyonlands (SW corner), the Salmon River corridor, and big chunks of the Snake River Plain. Free 14-day dispersed camping is the default on BLM land unless posted. The Owyhees are remote, signal-dead, and rocky -- carry recovery gear. BLM offices in Boise, Salmon, and Twin Falls publish current MVUM maps.
National Forests: Idaho has more National Forest land per capita than almost any state -- Sawtooth, Salmon-Challis, Payette, Boise, Caribou-Targhee, Nez Perce-Clearwater, Idaho Panhandle. Free dispersed camping along forest roads is standard; pack out everything. Fire restrictions kick in Jun-Sep most years. Trailheads near Stanley, McCall, and the Sawtooth NRA fill up summer weekends.
Stay limit: typically 14 days per location.
Service stops
Propane: Reliable in Boise, Coeur d'Alene, Idaho Falls, Pocatello, Twin Falls, and along I-84/I-15/I-90. Sparse in the Sawtooth valley (Stanley has one seasonal supplier), the Salmon River corridor, and US-12. U-Haul and Tractor Supply locations in larger towns handle refills reliably; rural ranch-supply stores often do too if you ask.
Dump stations: Idaho state parks all have free dump stations for paid guests. Flying J / Pilot stops along I-84 and I-15 charge $10-15. Forest Service campgrounds in the Sawtooth NRA and Payette NF have free dumps for guests. Boise, Twin Falls, and Idaho Falls have multiple commercial options.
Fuel: Diesel widely available along interstates. Long gaps to watch: US-12 Kooskia to Lolo (100+ miles, last reliable diesel in Kooskia), US-93 between Challis and Salmon (60 miles, station hours unreliable), Owyhee back roads (carry 5 extra gallons), and ID-21 between Lowman and Stanley (50 miles in summer, closed-impassable in winter). Idaho fuel taxes lower than neighbours -- fill up before crossing into Washington or Oregon.
Weather windows
Best monthsLate June through September for the mountains; April-October for the Snake River Plain. Daytime highs 70-90 F in summer; nights drop into the 30s above 6,000 ft even in July.
Avoid monthsNovember through April for the Panhandle, the Sawtooths, and anywhere over 5,000 ft. Many forest roads are unplowed; ID-21, US-12 (Lolo Pass), and ID-75 (Galena) close or chain-restrict regularly. The southern Snake River Plain stays drivable year-round but gets ice fog and freezing rain.
Snake River Plain wind is genuinely dangerous between Mountain Home and Burley on I-84. Sustained 30-40 mph crosswinds with 60 mph gusts roll a high-sided trailer fast. Watch ID 511 and pull off when warnings post -- there are signed wind shelters at most exits.
Emergency and road conditions
State patrolDial *477 (*ISP) from a cell phone for Idaho State Police non-emergency