WIS 49 begins at an interchange with Interstate 41 (I-41) north of Lomira and runs west from it, passing through Brownsville before curving to the north to meet the Dodge-Fond du Lac county line.

Shortly after exiting Waupun, the highway curves and starts running north to Brandon.

Shortly after exiting Brandon, the highway runs concurrently with WIS 44.

The highway runs north from the concurrent alignment shortly before it reaches Green Lake.

The extension was mostly paved but contained an unpaved section west of Brownsville.