Lone Rock is a city in Kossuth County, Iowa, United States. The population was 146 at the time of the 2020 census. The city is nameā¦Lone Rock is a city in Kossuth County, Iowa, United States. The population was 146 at the time of the 2020 census. The city is named after a large boulder. Lone Rock calls itself "The Neatest Little Town in Iowa."