Where Copper Creek drains into the Baraboo River, the highway follows the river in a southeasterly direction to Rock Springs, where it intersects WIS 154 and County Trunk Highway DD (CTH-DD).

The highway then runs north of the Baraboo River in an easterly direction from Rock Springs.

It intersects CTH-I and continues east and then starts running along Linn Street into West Baraboo.

The highway then reaches CTH-DL, and runs concurrently with it until ending at the entrance of Devil's Lake State Park.

A former WIS 136 designation running from the current route near North Freedom to Prairie du Sac was downgraded to a County Trunk Highway.