Sawtooth Scenic Byway

Shoshone to Stanley

Central Idaho · Idaho · United States

Key measurements

Distance

115.7 miles

Elevation gain

5,503 ft

Elevation loss

3,230 ft

High point

8,734 ft

Low point

3,952 ft

Net change

2,273 ft (3,970 ft to 6,243 ft)

Route type

point-to-point

Route Overview

This 115.7-mile route tracks one of Idaho's defining mountain transits, ascending from the high basalt desert of the Snake River Plain near Shoshone (elevation 3,951 ft) to the alpine basin of Stanley in the Sawtooth Range. Following State Highway 75 north, the road penetrates the Wood River Valley through Bellevue, Hailey, and Ketchum before entering the upper canyon of the Big Wood River. The geographic climax is the crossing of Galena Summit at 8,733.9 feet, after which the highway descends into the high Sawtooth Valley along the headwaters of the Salmon River.

Key Segments & Geographic Transitions

Snake River Plain to Bellevue — Miles 0.3–42.3

Leaving Shoshone, Highway 75 cuts across open sagebrush desert and irrigated agricultural lands on the northern expanse of the Snake River Plain. The road here features long, straight stretches and broad sightlines, ascending gently toward the southern toes of the Pioneer and Boulder ranges. Near the end of this segment, the open terrain narrows as the road passes through the mouth of the lower Wood River Valley at Bellevue.

Wood River Valley Corridor — Miles 43.3–52.8

This section forms the populated commercial spine connecting Bellevue and Hailey. Terrain remains relatively flat along the valley floor, but speed zones, traffic signals, local commuter flows, and turning vehicles slow overall momentum. Forested river bottoms and flanking mountain ridges tightly frame the highway as elevation rises past 5,000 feet.

Ketchum and Sun Valley Basin — Miles 53.6–60.1

Passing through Ketchum near the base of Mount Baldy, the route transitions from a working agricultural valley into a high-density mountain resort corridor. Expect lower speeds and heavy tourist pedestrian and vehicular traffic. Past town, the valley walls draw inward, and development quickly drops away as the highway enters the Sawtooth National Recreation Area.

Upper Big Wood River Canyon — Miles 60.7–69.3

Here the highway adopts a true mountain canyon profile. Following the winding course of the upper Big Wood River, the road curves through dense stands of Douglas fir and lodgepole pine. Curvature increases and the gradient steepens as the valley floor narrows into the approach toward the Boulder Mountains.

Galena Summit Pass to Stanley — Miles 70.1–115.6

The final, high-alpine stretch climbs via switchbacks to reach the route's high point at Galena Summit (Mile 84.3, 8,733.9 ft). The northern descent features dramatic shelf roads overlooking the headwaters of the Salmon River. Once on the valley floor, the highway tracks north through the wide, open Sawtooth Valley, bounded by the jagged Sawtooth Range to the west, before terminating in Stanley.

Seasonal & Environmental Context

With an elevation gain of over 4,700 feet from Shoshone to Galena Summit, environmental conditions shift radically along this route. Warm, arid weather in the low desert can instantly yield to cold temperatures at high elevation. Snow and ice frequently persist on Galena Summit well into late spring and can return by early autumn. Mid-summer afternoon thunderstorms routinely develop over the Sawtooth and Boulder mountains, producing sudden rain, localized wind gusts, and abrupt drops in temperature.

Logistics & Services

Fuel, food, and emergency services are concentrated along the lower half of the route in Shoshone, Bellevue, Hailey, and Ketchum. North of Ketchum (around Mile 60), services cease entirely for nearly 55 miles until reaching Stanley. Cell phone coverage becomes spotty north of Ketchum and is generally non-existent over Galena Summit and within the deeper pockets of the Sawtooth Valley.

Important Considerations

Large wildlife—predominantly deer and elk—presents a significant hazard along the upper Big Wood River canyon and throughout the Sawtooth Valley floor, particularly around dawn and dusk. Heavy seasonal tourist traffic and slow-moving recreational vehicles are common over Galena Summit, where passing zones are limited. Mountain weather can change quickly at altitude, making dramatic temperature drops common across the pass.