 The highway closely follows the route of the Old Spanish Trail through Dixie National Forest.SR-18 begins at Convention Center/Sunland Drive just south of the Bluff Street interchange with I-15 in St. George as an urban arterial and heads north through the west side of downtown St. George.After passing Sunset Boulevard (SR-8), the route has an inverted single-point urban interchange with Snow Canyon Parkway/Red Hills Parkway.