Rock Creek is a city in Pine County, Minnesota, United States. The population was 1,628 at the 2010 census. Portions of the Mille Lacs I…Rock Creek is a city in Pine County, Minnesota, United States. The population was 1,628 at the 2010 census. Portions of the Mille Lacs Indian Reservation are located within Rock Creek. Interstate 35 and Minnesota State Highway 70 are two of the main routes in the community. Rock Creek is mostly a rural area, made up of farm lands.