| State: | UT |
| Type: | US |
| Route: | 191 |
| Section: | 125 |
| Map Custom: | yes |
| Map Notes: | US 191 highlighted in red |
| Maint: | UDOT |
| Length Mi: | 404.168 |
| Length Round: | 3 |
| Length Ref: | [1] |
| Established: | 1981 |
| Direction A: | South |
| Terminus A: | towards Mexican Water, AZ |
| Direction B: | North |
| Terminus B: | towards Rock Springs, WY |
| Counties: | San Juan, Grand, Emery, Carbon, Duchesne, Uintah, Daggett |
| Previous Type: | SR |
| Previous Route: | 190 |
| Next Type: | SR |
| Next Route: | 193 |
U.S. Route 191 (US-191) is a major 404.168miles, north - south U.S. Numbered Highway through eastern Utah, United States. The present alignment of US-191, which stretches from Mexico to Canada, was created in 1981 through Utah. Previously the route had entered northern Utah, ending at US-91 in Brigham City, but with the completion of I-15 it was truncated to Yellowstone National Park and re-extended on a completely different alignment. In addition to a large portion of US-163, this extension absorbed several state routes: SR-33, most of SR-44, and SR-260.
US Route 191 enters Utah on Navajo Nation land and crosses mostly desolate parts of the state. The largest cities served by US-191 are Moab, Green River, Price, and Vernal. The highway nears the 10000feet level in 2 places in Utah, over Indian Summit near Price and again while crossing the Uintah Mountains near Vernal. It leaves Utah at Flaming Gorge Reservoir. US-191 directly or indirectly serves a number of parks in eastern Utah: Monument Valley Navajo Tribal Park, Glen Canyon National Recreation Area, Hovenweep National Monument, Natural Bridges National Monument, Capitol Reef National Park, Canyonlands National Park, Arches National Park, Dead Horse Point State Park, Utahraptor State Park, Dinosaur National Monument, and Flaming Gorge National Recreation Area.
Three portions of US-191 in Utah have been designated National Scenic Byways. Between U.S. Route 163 and State Route 95, US-191 forms part of the Trail of the Ancients. From Moab to Vernal, US-191 is a portion of the Dinosaur Diamond Prehistoric Highway. The Flaming Gorge-Uintas Scenic Byway begins at Vernal and follows US-191 to Flaming Gorge. The state has designated the portion from Helper to Duchesne as the Indian Canyon Scenic Byway, a Utah Scenic Byway.
Three portions of US-191 in Utah have restrictions on trucks and other large vehicles. Between the junctions with State Routes 46 and 279, vehicles wider than 15feet are required to have two police escorts. Between Vernal and the Wyoming State line, vehicles longer than 95feet are required to have two certified pilot escorts. Vehicles heavier than 20000lb per axle are prohibited on Flaming Gorge Dam.[2]
The independent portions of US 191 south of Interstate 70, as well as the concurrencies with I-70, US-6, and US-40, are included as part of the National Highway System.[3]
When US-191 was created in 1926, it did not enter Utah, only running from Idaho Falls northeast to Yellowstone National Park.[4] An extension in the late 1930s brought US-191 south to Brigham City, Utah, following what was then SR-41 and is now mostly SR-13.[5] With the construction of I-15 parallel to US-191, the latter route was removed from Utah in the early 1970s, and by 1980 it only existed north of Yellowstone.
In cooperation with Montana, Wyoming, and Arizona, the Utah Department of Transportation submitted an application to the American Association of State Highway and Transportation Officials (AASHTO) for an extension of US-191. In Wyoming, it would replace US 187 - a single-state route, which was against current AASHTO policy — and then follow Wyoming Highway 373 to the state line. The portion in Utah replaced several state routes — State Route 260 from Wyoming to Greendale Junction, the majority of SR-44 to US-40 in Vernal, and SR-33 from US-40 in Duchesne to US-6 near Price. After overlapping US-6 past Green River, the routing followed and replaced a large portion of US-163 to a junction southwest of Bluff. Between Bluff and Mexican Water, Arizona, US-191 followed a newly constructed road across the Navajo Nation, and then replaced State Route 63, still mostly inside the reservation, to I-40 at Chambers. (It has since been continued along former US 666 to Douglas on the Mexican border.)
The road from SR-6 (US-40) in Vernal north to SR-43 in Manila, where one could continue to Wyoming, was added to the state highway system in about 1918 as a forest highway project,[18] completed in 1926,[19] and numbered SR-44 in 1927.[20] It was the only state road connecting Daggett County's seat, Manila, with the rest of the state, yet parts remained in an unimproved condition through the 1950s.[21]
Several routes have been designated over the years to connect SR-44 to Flaming Gorge, a canyon on the Green River that lends its name to the Flaming Gorge Dam that US-191 now crosses the river on. The first was State Route 165, which would have begun at SR-44 south of Manila and headed east to the gorge. The state legislature added the proposed road to the state highway system in 1933,[22] but in 1935 it was deleted, and the number was reused to the west on a portion of Birch Creek Road.[23] Later, in 1941, the planned connection was redesignated as a state highway, this time State Route 220,[24] but in 1945 it was moved north, closer to the state line.[25] It was this alignment that was actually built, beginning at Linwood on SR-43 and proceeding east-southeasterly through a valley that is now flooded by the Flaming Gorge Reservoir's Linwood Bay.[26] SR-220 was deleted in 1957, but in its place was a new State Route 260 that began at Greendale Junction on SR-44 and headed northeast over the dam (then under construction) and to the state line. The legislature did not specify where it would intersect the border,[27] and the State Road Commission initially routed it along former SR-220 to Linwood.[28] However, the law was amended in 1963 to define the north end to be east of the reservoir,[29] and soon the lake began to fill, cutting off the road to Linwood (and inundating that settlement).[30] By 1981 the new road was completed, and most of SR-44 and all of SR-260 were absorbed by US-191.[31]