The St. Croix River winds through wild and scenic countryside from its origin in a spruce-tamarack swamp near Upper St. Croix Lake. The Namekagon joins the St. Croix forty-five miles upstream, and the river system ranges from swift, rocky whitewater to placid flowages on its way to the dam at St. Croix Falls thirty-six miles south. Historically, this river system served as a major highway for Native Americans, voyageurs, explorers, missionaries, and loggers. The Santee Sioux and Chippewa fought repeatedly for possession of the valuable rice lakes in the St. Croix basin, a conflict that lasted well into the nineteenth century. During the seventeen hundreds and eighteen hundreds, numerous outposts stood along the waterways in the quest to control the profitable fur trade. After the depletion of the beaver in the eighteen thirties, an eighty-year logging era began in the pineries along the river. Governor Knowles State Forest, established in 1970, and the St. Croix National Scenic Riverway, created in 1968, protect this valuable resource, and many thousands of people each year enjoy the recreational opportunities of the riverway and the state forest. The Northern States Power Company played a key role in establishing the National Scenic Riverway and the state forest by donating twenty-five thousand acres of land.