Cottonwood County Cottonwood County was organized July 29, 1870. It was named for the Cottonwood River, which touches the northeast corner of Germantown Township in Cottonwood County. The river was named for the abundance of cottonwood trees on its banks. Useful Websites: Cottonwood County City of Comfrey City of Jeffers City of Mountain Lake City of Westbrook City of Windom (county seat) Windom Chamber of Commerce