Title: St. Croix River (Wisconsin–Minnesota) - Wikipedia
Headings: St. Croix River (Wisconsin–Minnesota)
St. Croix River (Wisconsin–Minnesota)
Contents
Geography and hydrography
Conservation efforts
Naming
History
Fur trade
Logging
Cities and towns
Bridge crossings
Commerce and recreation
Further reading
See also
References
External links

Content: At that time, the Mid-Continent Rift rendered the middle of North America apart, creating a volcanic zone. The lava spewed forth cooled into hard basalt. That basalt is what today creates the dramatic cliffs around the Interstate State Parks. About 500 million years ago, a shallow sea covered the area, laying down layers of sand and minerals that make up much of the sandstone bluffs now seen along the river. In the last 20,000 years, glaciers have scraped the landscape and released torrents of meltwater, which carved the St. Croix River's course. The river has been home to people for thousands of years. A bison kill site in May Township, Washington County, Minnesota is believed to be about 4,000 years old. An Oneota village from about 1200 A.D. has been studied by archaeologists. At the time of European arrival in the region, the river valley and the surrounding area was occupied by the semi-nomadic Ojibwe, Dakota and nine other American Indian tribes. The Indians lived mainly on wild rice, fish, and game.