The highway intersects WIS 76 in Greenville then continues southeast for one mile (one point six kilometres) before turning east at the junction with CTH-CB.

WIS 15 then junctions with Interstate 41 (I-41) where it ends and Northland Avenue and CTH-OO begin in the Town of Grand Chute, just northwest of Appleton.

The first iteration followed present day US 41 from the Illinois border to Marinette via Milwaukee, Fond du Lac, Appleton and Green Bay.

The later highway continued straight on to intersect with Wisconsin Avenue (then US 10) at the north entrance road to the Fox River Mall in Appleton.

The entire length of WIS 15 was converted into a four-lane divided expressway as part of the project which was previously a two-lane undivided highway.