WIS 80 begins at the
Illinois state line as a continuation of
Illinois Route 84. It enters
Hazel Green, where
WIS 11 joins for a few miles. North of the end of the concurrency, WIS 80 passes through
Cuba City. Occasionally the highway aligns itself with the Grant-Lafayette county line. The highway enters
Platteville, where it meets
US 151 south of town and
WIS 81 in town. As WIS 80 leaves Platteville it heads north along the Iowa-Grant county line past
Livingston and into
Montfort. At Montfort, the highway joins with
US 18 for 8 miles before heading north from
Cobb, where the land becomes more forested. WIS 80 heads through
Highland.
WIS 133 joins WIS 80 west for five miles before WIS 80 heads north again from
Muscoda, where it crosses the
Wisconsin River. North of Muscoda, the highway passes through
Richland Center and Hub City before entering
Hillsboro and joins with
WIS 33/
WIS 82. The three-way concurrency leaves Hillsboro and enters
Union Center, where WIS 33 leaves the concurrency and WIS 80/WIS 82 go north to the southern trailhead of the
Elroy-Sparta State Trail, the northern trailhead of the
400 State Trail, and
Elroy. In Elroy, WIS 82 leaves the concurrency with WIS 80. WIS 80 continues north and leaves the
Driftless Area before entering
New Lisbon. North of New Lisbon it passes the junction with
Interstate 90/
Interstate 94 (I-90/94). North of New Lisbon the highway passes through the center of
Necedah, and the terrain is flat as it passes along the
Necedah National Wildlife Refuge and enters
Pittsville, where it merges with
WIS 73 and heading west for 2.5 miles. As it leaves the concurrency, it runs north through the farmlands of
Wood County, Wisconsin. WIS 80 ends at a roundabout junction with
US 10 just south of
Marshfield. WIS 80 crosses the
Wisconsin River into
Muscoda, which bills itself as the "Morel mushroom capital of Wisconsin".
WIS 133 joins WIS 80 east before WIS 80 heads south again to Highland and
Cobb, where the land continues to be hilly but becomes less forested and more rolling farmland. At Cobb, WIS 80 follows
US 18 west for before heading south along the Iowa–Grant county line past Livingston and into
Platteville, where it meets
WIS 81 in town and
US 151 south of town at the freeway bypass. South of Platteville, WIS 80 occasionally aligns itself along the Grant–Lafayette county line as it heads through
Cuba City and
Hazel Green, where
WIS 11 joins for a few miles. South of Hazel Green, WIS 80 ends at the
Illinois state line, where it meets
Illinois Route 84 (IL 84) west of the state's "Point of Beginning", the location from which most public land surveys in Wisconsin originated. ==Major intersections==