They connect MN 95 in Franconia Township, Minnesota with WIS 35 in Osceola, Wisconsin.

Highway 243 serves as a short route between Franconia Township and the village of Osceola.

The highway starts at MN 95 on Osceola Road and runs southeasterly for a short distance before it turns northeasterly and parallel to the St. Croix River.

[8] The current bridge was built in 1953 and rebuilt in 1980 by the Wisconsin Department of Transportation (WisDOT).

WisDOT also repaved their segment of the roadway, and they removed some rock from a bluff near the highway overlooking the river.