[4] In 2011, the route was decommissioned in an effort to reduce the amount of heavy truck traffic through downtown Decatur.

US 51) was a business loop that ran through the communities of Plover, Whiting, and Stevens Point.

The route was commissioned after a freeway bypass of the Stevens Point area was completed in 1971.

In 2019, the American Association of State Highway and Transportation Officials approved eliminating Bus.

US 51) is a business loop serving the communities of Rothschild, Schofield, and Wausau, Wisconsin.

The business loop was established in 1976 after a freeway bypass was completed east of Merrill.