U.S. Route 18 in Iowa

This article is about the section of U.S. Route 18 in Iowa. For the entire route, see U.S. Route 18.

U.S. Highway 18 marker
U.S. Highway 18
Map
US 18 highlighted in red
Route information
Maintained by Iowa DOT
Length311.750 mi[1] (501.713 km)
ExistedNovember 11, 1926[2]–present
HistoryPrimary Road 19 from 1920–1926[3]
National Parks Pike registered in 1920[4]
Major junctions
West end US 18 near Canton, S.D.
Major intersections
East end US 18 / WIS 60 at McGregor
Location
CountryUnited States
StateIowa
Counties
Highway system
← Iowa 17→ US 20

U.S. Highway 18 (US 18) is the northernmost east–west United States Numbered 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 about 312 miles (502 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.

  1. ^ Cite error: The named reference DOTGIS was invoked but never defined (see the help page).
  2. ^ Bureau of Public Roads & American Association of State Highway Officials (November 11, 1926). United States System of Highways Adopted for Uniform Marking by the American Association of State Highway Officials (Map). 1:7,000,000. Washington, DC: United States Geological Survey. OCLC 32889555. Retrieved November 7, 2013 – via Wikimedia Commons.
  3. ^ Official Auto Trails Map (Map). 1:1,081,344. Rand McNally. 1921. p. 330-331.
  4. ^ "Iowa Registered Routes". Iowa Department of Transportation. Retrieved September 15, 2011.