U.S. Route 18

U.S. Route 18 (US 18) is an east–west U.S. highway in the Midwestern United States. The western terminus is in Orin, Wyoming at an interchange with Interstate 25. Its eastern terminus is in downtown Milwaukee, Wisconsin. However, US 18 runs concurrent with other U.S. routes from its western terminus to Mule Creek Junction, Wyoming.

US 18 is one of the original United States highways of 1926. The US 18 designation was originally proposed for a road in Michigan from Grand Haven east to Detroit. This roadway was eventually designated as U.S. Route 16.

Route description

Wyoming

In Wyoming, US 18 runs concurrent with U.S. Route 20 from Interstate 25 to Lusk, where US 18 branches off to run concurrently with U.S. Route 85. At the unincorporated community of Mule Creek Junction in northeastern Niobrara County, US 18 leaves US 85. This ten-mile (16 km) stretch from US 85 to the South Dakota border is the only segment of US 18 in Wyoming which is not co-signed with another highway.

South Dakota

U.S. Route 18 in Iowa

U.S. Highway 18 (US 18) is the northernmost east–west U.S. Highway in the state of Iowa. As with all state highways in Iowa, it is maintained by the Iowa Department of Transportation (Iowa DOT). It enters the state by crossing the Big Sioux River between Inwood and Canton, South Dakota. It travels 311 miles (501 km) and connects Spencer, Mason City and Charles City. The highway leaves the state via the Marquette–Joliet Bridge over the Mississippi River at Marquette. Prior to becoming a U.S. Highway, the route US 18 follows was known as Primary Road No. 19 and the National Parks Pike.

Route description

US 18 begins at the Big Sioux River approximately 2 miles (3.2 km) east of Canton, South Dakota. It runs easterly through rural Lyon County, in the northwestern corner of the state. At Inwood it meets Iowa 182, which provides access to Sioux Falls, South Dakota, via Iowa 9 and South Dakota Highway 42. US 18 turns south at Inwood and heads into Sioux County. The highway crosses the Rock River on its way towards Rock Valley and Hull. West of Hull, at Perkins, US 18 juts to the south along US 75 before turning east again closer to Hull. The highway continues east towards Sheldon.

U.S. Route 18 in Wisconsin

In the U.S. state of Wisconsin, U.S. Route 18 (normally called U.S. Highway 18, Highway 18 or US 18) runs east–west across the southern part of the state. The highway serves as major connecting route between Madison and the southwest corner of the state. East of Madison, the route parallels Interstate 94 and serves as a local connection route to the communities along the interstate. US 18 enters Wisconsin at Prairie du Chien and ends in downtown Milwaukee at Lincoln Memorial Drive, across from the Milwaukee Art Museum.

Route description

US 18 enters Crawford County from Iowa, crossing the Mississippi River using the Marquette-Joliet Bridge just west of Prairie du Chien. WIS 60 begins at the state line and runs concurrent with US 18 east from there. The two highways turn south at the along with Wisconsin Highway 35 downtown and head southeast out of the city. WIS 60 branches northeast from US 18 at Bridgeport. US 18 and WIS 35 continue southeast into Grant County The two highways split at Patch Grove with WIS 35 continuing southeastward along with WIS 133 south, while US 18 turns eastward along with WIS 133 north. WIS 133 branches north at Mount Hope. US 18 and US 61 junction in downtown Fennimore. and WIS 80 north joins the highway in Montfort, on the Iowa County line.