The segment between Pukwana and Platte was redesignated as part of South Dakota Highway 43 c. 1939, and SD 47 was rerouted west from Chamberlain to Oacoma, then extended southward to U. S. 18 at Gregory.

11 years later, c. 1950, SD 47 was extended south to the Nebraska border, via a shared alignment with U. S. 18 to Burke.

In 1955, near Oacoma, SD 47 was rerouted west to near Reliance, before heading south to meet with the old alignment near the White River.

In 1976, the segment between Ft. Thompson and Reliance, which had previously passed through Chamberlain and Oacoma, was rerouted onto the more direct road formerly known as South Dakota Highway 47W,[4] which had been constructed around 1965.

This designation was used only for 10 years; it was made part of South Dakota Highway 47 when a portion of that route was realigned.