Savanna Army Depot was a 13,062-acre (52.86 km²) installation, located on the eastern bank of the Mississippi River, in Carroll and Jo Daviess counties, around seven miles (11 km) north of Savanna, Illinois. It was opened in 1917 as a proving and testing facility for weapons developed at Rock Island Arsenal. In 1921 it became a weapons depot. It became a Superfund site on October 15, 1984. It was selected for closure through the Base Realignment and Closure process in July 1995 and was officially closed on March 18, 2000. The Jo-Carroll Local Redevelopment Authority (LRA) was established to redevelop a portion of the property for commercial and business usage referred to as the Savanna Depot Park. On September 26, 2003, the United States Department of Defense agreed to transfer 9,404 acres (38.06 km²) of land to become the Lost Mound Unit of the Upper Mississippi River National Wildlife and Fish Refuge. 3,022 acres (12.23 km²) were initially transferred with the rest to be transferred following environmental cleanup. The portion near Lock and Dam No.