Rocksbury Township is a township in Pennington County, Minnesota, United States. The population was 1,077 at the 2000 census. Rocksbury Township was named for Martin Rockstad, a pioneer farmer. According to the United States Census Bureau, the township has a total area of 34.8 square miles, of which 34.3 square miles is land and 0.5 square mile …Rocksbury Township is a township in Pennington County, Minnesota, United States. The population was 1,077 at the 2000 census. Rocksbury Township was named for Martin Rockstad, a pioneer farmer. According to the United States Census Bureau, the township has a total area of 34.8 square miles, of which 34.3 square miles is land and 0.5 square mile is water.