LARGEST U.S. COUNTIES BY LAND AREA EAST OF THE MISSISSIPPI RIVER

The 29 largest counties* in the U.S. by area are all west of the Mississippi River. The two largest counties east of the Mississippi are St. Louis County, Minnesota and Aroostook County, Maine. They are the 30th and 31st largest counties by area in the U.S. The determination of the area of a county is dependent upon whether the total area includes both land and water surface. Saint Louis County, Minnesota has a total area (land and water) of 6,859.91 square miles, making it the 30th largest county by area in the U.S. However, Aroostook County, Maine has a land surface area of 6,671.54 square miles, compared to Saint Louis County’s area of 6,225.16 square miles, making Aroostook County larger than St. Louis County in land surface area only. So, which is the largest county by area east of the Mississippi? People from Saint Louis County, Minnesota say it’s St. Louis County and people from Aroostook County say it’s Aroostook County. *Alaska does not have counties.