This page profiles Interstate 15 in Northern Utah.
Interstate 15 North and Interstate 84 West
Just east of Brigham City, U.S. 91 emerges from the shadow of Interstate 15 for the first time. An expressway, U.S. 91 travels due east to meet U.S. 89 in Brigham City, and the two routes merge together en route to Logan, where the routes divide. Photo taken by Casey Cooper, 07/09/05.
U.S. 91 was a major north-south route through the Intermountain West. Originating in Long Beach, California, the route angled northeast along what is today California 91, Interstate 215, and Interstate 15 through Riverside, San Bernardino, Barstow, and Baker. Entering Nevada, U.S. 91 followed the old Arrowhead Highway through the Mojave Desert, into Las Vegas, and northeast through Arizona and into St. George, Utah. Interstate 15 replaced U.S. 91 through most of Utah, all the way through Cedar City, Nephi, Provo, and Salt Lake City. However, here at Brigham City, the routes diverge for the first time: Interstate 15 follows old U.S. 191 north into Idaho, while U.S. 91 follows its traditional route toward Logan. U.S. 91 only exists for a short time; it ends in Idaho Falls at the junction with Business Loop I-15 and U.S. 26. Photo taken by Casey Cooper, 07/09/05.
Northbound Interstate 15 and westbound Interstate 84 reach Exit 364, Junction U.S. 91 north. This is a trumpet interchange. There is no END shield on southbound U.S. 91. U.S. 91 was removed in stages from existence: 1964, eliminated south of Barstow; 1966, eliminated between Barstow and Baker; 1970, eliminated between Baker and California-Nevada State Line; 1974, eliminated California-Nevada State Line to Nevada-Arizona State Line; 1972, eliminated Nevada-Arizona State Line to Brigham City. Photo taken by Casey Cooper, 07/09/05.
Interstate 15 and Interstate 84 are well-signed on their shared alignment between Ogden and Tremonton. Photo taken by Casey Cooper, 07/09/05.
Interstate 15 and Interstate 84 prepare to split. To the Pacific Northwest, including Boise, Idaho; Portland, Oregon, and Seattle, Washington, follow Interstate 84 (former Interstate 80N until 1980) west. To eastern Idaho and Montana, including Pocatello, Idaho; Idaho Falls, Idaho; and Butte, Montana, follow Interstate 15 north. Interstate 15 continues north to the International Border with Canada, where it enters Alberta. Photo taken by Casey Cooper, 07/09/05.
The two left lanes continue as westbound Interstate 84; the two right lanes exit onto Interstate 15 northbound. This diagram sign shows three left lanes heading west on Interstate 84, but that is incorrect. Photo taken by Casey Cooper, 07/09/05.
Here is a view of both directions of traffic just south of the Interstate 15/Interstate 84 split near Tremonton. Photo taken by Casey Cooper, 07/09/05.
This view of the split between Interstate 15 and Interstate 84 demonstrate the fact that only two lanes continue west on Interstate 84, and the right two lanes angle north onto Interstate 15. The connection of Interstate 15 to Interstate 84 was constructed after the original freeway was built; in fact, the gap north of Tremonton was one of the last sections of Interstate 15 freeway to be constructed in Utah (not until the early 1980s). Photo taken by Casey Cooper, 07/09/05.
A standalone trailblazer for Interstate 15 reminds northbound motorists to stay in the right two lanes. Interstate 15 follows former U.S. 191 north to Portage at the state line, then continues into Idaho. U.S. 191 was decommissioned in favor of Interstate 15 in 1972, and it did not reappear in the state until 1982, when it was extended south from Rock Springs, Wyoming, through eastern Utah all the way to Interstate 40 near Holbrook, Arizona. Meanwhile, the former companion to Interstate 84 was U.S. 30S, and it was decommissioned in 1972 as well. U.S. 30 now follows the old route of U.S. 30N, and Interstate 84 meets U.S. 30 for the first time near Burley and Rupert. Photo taken by Casey Cooper, 07/09/05.
