Columbus is a city in Anoka County, Minnesota, United States. The population was 3,914 at the 2010 census. The city was known as Col…Columbus is a city in Anoka County, Minnesota, United States. The population was 3,914 at the 2010 census. The city was known as Columbus Township until September 21, 2006, when it was incorporated as the city of Columbus, in response to concerns that the adjacent city of Forest Lake was planning to annex portions of the township.