Stillwater, city, seat (1851) of Washington county, eastern Minnesota, U.S. It lies on the St. Croix River (bridged to Wisconsin), at the head of Lake St. Croix, about 20 miles (30 km) northeast of St. Paul. Sioux and Ojibwa Indians were early inhabitants of the area, which was originally part of Wisconsin Territory. One of Minnesota’s oldest communities, it was first settled by trader Joseph Renshaw Brown in 1839 and called Dakotah. The city was officially founded in 1843 with the incorporation of the Stillwater Lumber Company and was renamed for the stillness of the lake’s water. It was laid out in 1848 and was the site of the convention (August 26, 1848) that led to the formation of Minnesota Territory in 1849. More mills were built in the 1850s, and Stillwater became a lumbering centre as logs were floated down the St. Croix from northern forests. The industry ended in the early 20th century, with the last logs passing through in 1914. Tourism is now a major focus of the economy, and the city has many historic buildings (including a courthouse dating from 1870). Manufactures include plastic molds, automotive parts, windows, and medical supplies, and agriculture includes corn (maize), soybeans, and nursery crops. There are two state prisons in the city. A museum chronicles the city’s logging history. Stillwater is part of the St. Croix National Scenic Riverway, and William O’Brien and Willow River state parks are nearby. A fossilized face of sandstone is exposed nearby along the St. Croix. Inc. 1854. Pop. (2000) 15,143; (2010) 18,225.