It is named after the Trempealeau River, which flows through the county.
The seat is Whitehall, while the largest city is Arcadia.
It borders Buffalo, Eau Claire, Jackson and La Crosse Counties in Wisconsin, as well as Winona County in Minnesota.
Main highways include I-94, US-10, US-53, WI-35, WI-54, WI-93 and WI-95.
Cities
Dodge