It is named for Nathan Dane, who helped carve out the Wisconsin Territory.
The seat and largest city is Madison. This is the second most populous county in Wisconsin.
It borders Columbia, Dodge, Green, Iowa, Jefferson, Rock and Sauk Counties.
Main highways include I-90/I-39, I-94, US-12, US-14, US-18, US-51, US-151, WI-19 and WI-30.