The county has an area of , of which is land and (2.3%) is water. The Blue Earth River and Le Sueur River flow through a part of the county. The land surface is relatively flat with over 30 lakes in the county. There are many "closed forest savannas" that some call the big woods in the county's northeast. The rivers that flow out of the northeast are surrounded by these big woods. Most of the county is grassland prairie but scattered parts are wet prairie. Some spots that surround the rivers are oak openings and barren brushland.
The county has an area of  of which is land and (23%) is water The Blue Earth River and Le Sueur River flow through a part of the county The land surface is relatively flat with over 30 lakes in the county There are many "closed forest savannas" that some call the big woods in the county's northeast The rivers that flow out of the northeast are surrounded by these big woods Most of the county is grassland prairie but scattered parts are wet prairie Some spots that surround the rivers are oak openings and barren brushland