- Wisconsin (Wikipedia)
Wisconsin (/wɪˈskɒnsɪn/) is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north.
- St. Croix River (Wisconsin–Minnesota) (Wikipedia)
The St. Croix River (/ˈseɪnt ˈkrɔɪ/ SAYNT KROY; literally “holy cross” in French) is a tributary of the Mississippi River, approximately 169 miles (272 km) long, in the U.S. states of Wisconsin and Minnesota. The lower 125 miles (201 km) of the river form the border between Wisconsin and Minnesota. The river is a National Scenic Riverway under the protection of the National Park Service. A hydroelectric plant at the Saint Croix Falls Dam supplies power to the Minneapolis–St. Paul metropolitan area.
- Mississippi River (Wikipedia)
The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for 2,340 miles (3,766 km) to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi’s watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The main stem is entirely within the United States; the total drainage basin is 1,151,000 sq mi (2,980,000 km2), of which only about one percent is in Canada. The Mississippi ranks as the thirteenth-largest river by discharge in the world. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana.
- Prescott is a city in Pierce County, Wisconsin at the confluence of the St. Croix River and Mississippi River. The population was 4,258 at the 2010 census, making it the second-largest city in the county after River Falls, and the largest entirely within Pierce County.
- Empty set (Wikipedia)
In mathematics, the empty set is the unique set having no elements; its size or cardinality (count of elements in a set) is zero. Some axiomatic set theories ensure that the empty set exists by including an axiom of empty set, while in other theories, its existence can be deduced. Many possible properties of sets are vacuously true for the empty set.
- Hastings, Minnesota (Wikipedia)
Hastings (/ˈheɪstɪŋz/ HAY-stingz) is a city mostly in Dakota County, Minnesota, of which it is the county seat, with a portion in Washington County, Minnesota, United States. It is near the confluence of the Mississippi, Vermillion, and St. Croix Rivers. The population was 22,154 at the 2020 census. It is named for the first elected governor of Minnesota, Henry Hastings Sibley.