 Although SR-186 was a hidden legislative designation along the path of US-40A, the portion of 400 South between 300 West (where US-40 ran) and Redwood Road (SR-68) was solely SR-186 by 1941, and was signed as such.By 1948, the path of US-40A (hidden SR-186) ran from US-40 at the mouth of Parleys Canyon northwesterly along Foothill Drive until turning west on Sunnyside Avenue, north on 1300 East and west on 500 South and 400 South before terminating at 300 West, which then carried the designations of US-40, US-89, and US-91.By 1954, Foothill Drive was extended north past Sunnyside Avenue toward the University of Utah, and US-40A was rerouted along this new stretch of road.