A practical Sawtooth Scenic Byway road trip itinerary: an 8-day Idaho loop from Boise through Stanley, Sun Valley and Craters of the Moon, with driving times and pacing.
Idaho's central mountains hold some of the least crowded big scenery in the American West, and this loop links the best of it from a single base in Boise. This Sawtooth Scenic Byway road trip itinerary runs for eight days through two of the state's great scenic byways, a chain of granite peaks and alpine lakes, and a finale among black volcanic lava fields. The driving days are short, the towns are walkable, and the night skies are some of the darkest in the country.
The loop starts and finishes in Boise. It climbs north on the Ponderosa Pine Scenic Byway (Highway 21) through the old gold-rush town of Idaho City to Stanley, then crosses Galena Summit on the Sawtooth Scenic Byway (Highway 75) to Ketchum and Sun Valley. From there it makes a short hop east to Craters of the Moon National Monument before the long, easy run west back to Boise. It joins two of Idaho's signature drives into one circuit, with a volcanic twist at the end.
This is a scenic, outdoors-led drive rather than a city trip. It suits travellers who like mountain towns, alpine lakes, hot springs and big empty landscapes, and who are happy with a mix of easy hikes, paddling and slow scenic driving. Any car handles the route in summer, and most days involve only an hour or two behind the wheel.
Eight days is comfortable: two nights each in Boise, Stanley and the Sun Valley area, plus a night out at Craters of the Moon. With less time you could cut Idaho City to a quick stop and drop a night in Boise; with more, add days for longer hikes above Redfish Lake or a rafting trip on the Salmon River.
Start in Boise, where the foothills meet the high desert. Walk the Boise River Greenbelt, wander the downtown and the historic Basque Block, and use the city to sort your car and supplies before the mountains. This is the gateway to the Ponderosa Pine Scenic Byway north.
Highway 21 climbs into the pines to Idaho City, an 1860s gold-rush town that was once the largest settlement in the Northwest. Stroll the wooden boardwalks and timber storefronts and visit the pioneer cemetery before carrying on over Mores Creek Summit toward the Sawtooths.
Stanley is the wild heart of the route, a tiny town directly beneath the granite spires of the Sawtooth Range. Use two nights here. Swim or paddle at Redfish Lake, soak in free riverside hot springs such as Sunbeam, hike Fishhook Creek, and stay up for the Milky Way over the Central Idaho Dark Sky Reserve.
Eight days through the finest UNESCO towns of Bohemia and Moravia: Prague's Astronomical Clock, the bone church of Kutná Hora, Telč's Renaissance square, the fairy-tale castle bend of Český Krumlov and Pilsner Urquell in Plzeň.
The Sawtooth Scenic Byway crosses Galena Summit, with its grand overlook of the Salmon River headwaters, and drops to Ketchum and Sun Valley. Ketchum is a walkable former mining town; neighbouring Sun Valley opened in 1936 as North America's first destination ski resort. Ride the Bald Mountain lift, cycle the paved trails along the Big Wood River, or visit Ernest Hemingway's grave.
Drive an hour east to Craters of the Moon National Monument, a sea of black lava, cinder cones and lava tubes formed along the Great Rift. Drive the seven-mile Loop Road, walk the Devil's Orchard, climb Inferno Cone and explore the caves with a free permit. Then take Highways 20 and 26 west across the Camas Prairie to close the loop back in Boise.
Give the mountains the time. Stanley and the Sun Valley area each deserve two nights, while Idaho City works as a half-day or a quiet overnight. Save Craters of the Moon for a focused half-day before the long drive west, and aim to visit in the morning so the final leg into Boise is in good light.
Late June to September is the window. Highway 21 between Lowman and Stanley usually closes in winter and reopens around April, and the Loop Road at Craters of the Moon is closed roughly November to spring. Summer brings warm, dry days, with lake swimming at its best in July and August. Early autumn is quieter and cooler, with the first golden aspens in the high valleys.
This is a self-drive loop and any car copes in summer. Distances between towns are short, so the only long day is the return from Craters of the Moon to Boise. Fuel is reliable in Boise, Ketchum and Hailey but sparse in between, so top up before mountain stretches. Check Highway 21 status before setting out, as the Lowman to Stanley section is seasonal.
Mountain weather changes quickly, so carry layers even in summer and start hikes early to avoid afternoon storms. The lava fields at Craters of the Moon are hot and shadeless, so bring plenty of water. Book Stanley lodging well ahead, as beds there are limited, and reserve summer accommodation in Sun Valley during festival season.
Ready to plan it in detail? Use our full Idaho Sawtooth route below to see every stop, driving leg and overnight on the map.
From Cambridge's Gothic spires to Ely's cathedral rising above the flat Fens, this journey through Cambridgeshire takes in Bronze Age causeways, a Norman cathedral with a theatrical three-arched West Front, and Stamford, England's finest stone town.
The full route — stops, maps, and driving times — is on Routebook by Kington.
An 8-day loop from Boise linking Idaho's two great mountain byways: the Ponderosa Pine and Sawtooth Scenic Byways through Stanley and Sun Valley, with a finale at the lava fields of Craters of the Moon.
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