WIS 15 begins at the junction of US 45 and County Trunk Highway T (CTH-T) in the Town of Hortonia (just southeast of New London) as a two-lane road and heads southeast to Hortonville.
WIS 15 begins at the intersection of US 45 and County Trunk Highway T (CTH-T) in the Town of Hortonia (southeast of New London), starting as a two-lane road, and travels southeast to Hortonville.