Bollinger County is a county located in the southeastern part of the U.S. state of Missouri. As of the 2020 census, the county's population was 10,567. The county seat, largest and only city, is Marble Hill. The largely rural county is supported by agriculture and construction. The county was officially organized in March 1851 from portions of Wayne, Cape Girardeau and Stoddard Counties, and named in honor of George Frederick Bollinger, an early settler.

Cape Girardeau County is located in the southeastern part of the U.S. state of Missouri; its eastern border is formed by the Mississippi River. At the 2020 census, the population was 81,710. The county seat is Jackson, the first city in the US to be named in honor of President Andrew Jackson. Officially organized on October 1, 1812, the county is named after Ensign Sieur Jean Baptiste de Girardot, an official of the French colonial years. The "cape" in the county's name is named after a former promontory rock overlooking the Mississippi River; this feature was demolished during railroad construction. Cape Girardeau County is the hub of the Cape Girardeau–Jackson metropolitan area. Its largest city is Cape Girardeau.