Interstate Park consists of adjoining Minnesota and Wisconsin state parks at the Dalles of the St. Croix River, where the river cuts a deep basalt gorge between Taylors Falls and St. Croix Falls. The parks preserve striking geology shaped by the Midcontinent Rift, later seas, and powerful glacial meltwater that carved the gorge and its remarkable potholes, including the famous Bottomless Pit. The area was long used by Native Americans, later by fur traders and loggers, and became a tourist destination in the 19th century. Preservation efforts led Minnesota to establish its park in 1895 and Wisconsin in 1900, creating the first interstate parkland collaboration in the United States.