Allendale is best known as being home to the main campus of Grand Valley State University. The Allendale ZIP code 49401 serves all of the CDP. The 49401 ZIP code also serve portions of southern Allendale Township not included in the CDP as well as portions of Blendon Township to the south and Georgetown Township to the southeast. Allendale is named for the township. Malta was initially chosen as the name for the township, however when the township was organized in 1849, state senator Pennoyer changed the name to Allendale, after Agnes Allen, the first person on the tax roll in the area and the widow of Hannibal Allen, who was the son of Revolutionary War hero Ethan Allen.