West of the river, the land elevates from lack of glaciation and joins the Driftless Area, known for its abrupt hills and valleys, covering most of southwest Wisconsin.

From its source, the river meanders southeast, past Paoli and Belleville, where it is dammed to form Lake Belle View.

It crosses into northern Illinois flowing past an extensive area of the Forest Preserves of Winnebago County system.

The Sugar River State Trail is a 24 miles (39 km) abandoned railroad line used for walking, bicycling, snowmobiling, and cross-country skiing.

[3] Accidents and drowning deaths have occurred on the river; some as the result of excessive drinking, high current, or a combination of both.