the Omaha, Rosebud and Black Hills Highway and the Custer Battlefield Trail. Towns along the road include Gregory, Winner, Olivet, Mission, Martin, Batesland, and Pine Ridge. Nearby towns and locales of interest include Rosebud (capital of the Rosebud Sioux Tribe), and Wounded Knee. Legal definition The South Dakota section of U.S. 18, other than the concurrency with Interstate 29, is defined at South Dakota Codified Laws § 31-4-141. Iowa U.S. 18 enters Iowa via a Big Sioux River crossing northeast of Beloit. It overlaps U.S. Route 75 for a mile near Hull and U.S. Route 59 for a mile near Sanborn. It then overlaps U.S. Route 71 through Spencer. U.S. 18 passes through Emmetsburg before intersecting U.S. Route 169 at Algona. U.S. 18 then continues east through Garner before intersecting Interstate 35 in Clear Lake. After a brief concurrency with I-35, U.S. 18 continues as a freeway bypassing Mason City to the south. At Charles City, U.S. 18 becomes a rural two-lane highway again, except for a brief concurrency with the U.S. Route 63 bypass of New Hampton. After passing through West Union, it turns northeast and joins U.S. Route 52 at Postville, then leaving 52 about east of Monona before crossing the Mississippi River into Wisconsin via the Marquette–Joliet Bridge in the city of Marquette. U.S. 18 is the designated route of the Avenue of the Saints between Clear Lake and Charles City. Wisconsin Upon entry into Wisconsin at Prairie du Chien, US 18 is the terminus for WIS 60. The two routes are then concurrent until Bridgeport where WIS 60 splits off to the east and US 18 crosses the Wisconsin River and turns east on the other side. The route joins the US 151 expressway in Dodgeville and the two remain concurrent east to Madison (See U.S. Route 151 in Wisconsin for an interchange list). US 18 follows US 12 south of Madison and passes through or around Cambridge, Jefferson and Waukesha before terminating in Milwaukee at the junction of East Michigan Street and Lincoln Memorial Drive in downtown. Major intersections Wyoming in Orin. US 18/US 20 travel concurrently to Lusk. in Lusk. The highways travel concurrently to the northeastern part of Niobrara County. South Dakota in Hot Springs. The highways travel concurrently to Oelrichs. west of Mission. The highways travel concurrently to Mission. southeast of Witten. The highways travel concurrently to Colome. east-southeast of Fairfax. The