According to the 2010 census, Kaskaskia has a total area of , all land. However, the village comprises only a small part of Kaskaskia Precinct, which includes all of Randolph County's land west of the Mississippi. The precinct forms an exclave of Illinois within Missouri. Kaskaskia Precinct has a land area of and a 2000 census population of 36 people. In 1993 the Mississippi River almost completely flooded the island.