Land for sale in Allegan County, Michigan, recently totaled approximately $282 million and approximately 100,000 acres. Based on the combined acreage of land and rural property for sale here, Allegan County has the most land for sale of the 83 counties in the Mitten State. There were two properties listed as sold in Allegan County through the Land Network Comparable Sales Program. This represented a total value of $850,000. Allegan had the most land for sale. Manufacturing and related services are the largest economic sectors in Allegan County. Allegan County is Michigan's 14th largest county (1,833 square miles). It's located in the Southwest Michigan region of the state.