[2][3] WYO 258 heads south and crosses the North Platte River before intersecting W. 13th Street, which also provides access to Fort Caspar.

Continuing south, WYO 258 passes along the western side of the Central Wyoming Fair Grounds and briefly parallels the North Platte River a short distance before intersecting Wyoming Highway 220 (CY Avenue), the main artery for traffic coming into Casper from the west.

[3] Now mainly directed north, WYO 258 travels through the eastern neighborhoods of Casper and intersects busy east-west 2nd Street.

Casper's Eastridge Mall[1] lies on the southeastern side of this intersection.

Just past the interstate, WYO 258 reaches its eastern end at US 20/US 26/US 87 (Yellowstone Highway) after 10.58 miles (17.03 km).