In 1976, the route was designated as South Dakota 49, with the number extended to the junction with South Dakota Highway 44. In 1984, the route was further extended to Colome, at the junction of U.S. 18 and U.S. 183.
In 1976, the route was named South Dakota 49, with the number extended to the intersection of South Dakota Highway 44. In 1984, the route was further extended to Colome, at the junction of U.S. 18 and U.S. 183.