It is named after the Buffalo River, which flows through the County.
The seat is Alma, while the largest city is Mondovi.
It borders Pepin, Eau Claire and Trempealeau Counties in Wisconsin, as well as Winona and Wabasha Counties in Minnesota.
Main highways include US-10, WI-25, WI-35, WI-37 and WI-54.
CN Trempealeau River Bridge #9