U.S. Route 91

U.S. Route 91 is a north–south United States Numbered Highway that once extended from Long Beach, California to the Canada–United States border near Brigham City, Utah and Montana. The modern alignment is a much shorter corridor primarily within Utah and Idaho, connecting metropolitan areas such as Salt Lake City, Provo and Idaho Falls while paralleling major corridors like Interstate 15 and historic routes including the Lincoln Highway and the Old Spanish Trail.

Route description

The current alignment in Utah begins near Provo at an interchange with Interstate 15, passes through Utah Valley adjacent to Utah Lake, and follows the Wasatch Front northward toward Salt Lake City suburbs including Orem and Sandy. From there the route continues into northeastern Utah toward the Cache Valley, traversing or bypassing communities such as Logan and Brigham City before crossing into Idaho. In Idaho the highway serves Preston and Pocatello before reaching Idaho Falls and continuing north toward Blackfoot and Montpelier. North of the Snake River Plain the route approaches the Teton Range and the Yellowstone National Park gateway region, intersecting with state routes linked to Grand Teton National Park and Jackson Hole. The alignment meets the Idaho State Highway System and terminates near the Montana line, connecting with corridors toward Butte and Helena.

History

The original 1926 designation of U.S. highways assigned the number through the Great Basin and Intermountain West, routing from Long Beach through Los Angeles, Bakersfield, Las Vegas, Salt Lake City and Butte to Sweetgrass at the Canada–US border. The corridor paralleled early auto trails such as the Victory Highway and the Lincoln Highway spurs and served as a primary link for travelers between the Pacific Coast and the Canadian Rockies. Postwar growth and the authorization of the Interstate Highway System in 1956, championed by figures like President Dwight D. Eisenhower, led to construction of Interstate 15 which duplicated much of US 91's function. Over the 1950s–1970s many segments were bypassed, truncated, or decommissioned, reflecting shifts similar to those that affected U.S. Route 66 and other historic US routes. State highway agencies such as the Utah Department of Transportation and the Idaho Transportation Department reclassified former alignments as state routes and business loops. Notable civic and commercial developments along the route involved municipalities like Long Beach and Las Vegas and institutions such as Brigham Young University and Idaho State University in Pocatello. Preservation efforts and historic highway tourism have highlighted segments near Salt Lake City and near national park gateways including Yellowstone National Park.

Major intersections

The corridor historically and currently intersects numerous major corridors and cities: - Southern terminus (historical): Long Beach, California — junctions with coastal routes and US 101. - Los Angeles area intersections with arterial routes serving Hollywood and Pasadena. - Bakersfield and Las Vegas crossings with transcontinental and regional arterials. - In Utah major connections with Interstate 15 near Provo and Salt Lake City, interchanges serving Ogden and Brigham City. - In Idaho intersections with I-86 at Pocatello, and junctions with routes to Idaho Falls and Blackfoot. - Northern approaches connect with U.S. Route 20 and state highways toward Yellowstone National Park and onward corridors to Butte and Helena.

Spur and related routes

Over time numerous spurs, business loops, and alternate alignments were designated, often rebranded by state systems. Examples include business loops through Las Vegas and Bakersfield, short connectors serving university towns such as Provo and Pocatello, and memorial or historic designations in communities like Brigham City. Several former alignments now carry state route numbers administered by the Nevada Department of Transportation, the Caltrans district network in California, the Utah Department of Transportation, and the Idaho Transportation Department. Local business routes link downtown cores such as Logan and Idaho Falls to interstates, reflecting patterns similar to former spurs of U.S. Route 66.

Future and improvements

Planned and potential improvements focus on safety, capacity, and historic preservation. Agencies including the Federal Highway Administration coordinate with state DOTs on projects to upgrade segments parallel to Interstate 15 and to improve multimodal access near institutions like Brigham Young University and Idaho State University. Regional transportation plans for the Wasatch Front Regional Council and the Eastern Idaho Regional Transit District identify intersection upgrades, pavement rehabilitation, and signage to support tourism to Yellowstone National Park and Grand Teton National Park. Preservation groups and municipal governments in Salt Lake City, Las Vegas, and Long Beach continue cultural heritage campaigns to mark historic alignments and maintain interpretive sites.

Category:U.S. Highways Category:Historic trails and roads in the United States