After passing Sunset Boulevard (SR-8), the route has an inverted single-point urban interchange with Snow Canyon Parkway/Red Hills Parkway.

The route has a dumbbell interchange at Ledges Parkway as it continues north, passing through Snow Canyon State Park.

[3] This portion of the trail is known for the 1857 Mountain Meadows massacre, a controversial event in both Utah and Mormon history which occurred just off what is now SR-18.

[4] A 1927 law gave it the number and extended it west to the Nevada state line, where it became SR 25 to Panaca.

[6] A branch from Enterprise west to Nevada, where SR 75 continued as a shortcut to Panaca, was added to SR-18 in 1941,[7] but split off as SR-120 in 1945.