Portage is a city in and the county seat of Columbia County, Wisconsin, United States. The population was 10,581 at the 2020 census, making it the largest city in Columbia County. The city is part of the Madison Metropolitan Statistical Area.

The Wisconsin River is a tributary of the Mississippi River in the U.S. state of Wisconsin. At approximately 430 miles long, it is the state's longest river. The river's name was first recorded in 1673 by Jacques Marquette as "Meskousing", which is rooted in the Algonquian languages used by the area's Native American tribes. The river's original meaning is obscure, but French explorers who followed in the wake of Marquette later modified the name to "Ouisconsin", and so it appears on Guillaume de L'Isle's map. This was simplified to "Wisconsin" in the early 19th century, before being applied to Wisconsin Territory and finally the state of Wisconsin.