William O'Brien State Park

The John Copas House is a historic house in the unincorporated community of Copas, Minnesota, United States. Its original owner was an Italian immigrant who settled the property in the early 1850s and built this house around 1880 to enlarge or replace his previous residence. The house was listed on the National Register of Historic Places in 1980 for its local significance in the themes of architecture and exploration/settlement. It was nominated for its association with John Copas, an early settler and leading figure in the community platted in 1857 and ultimately named in his honor.

Copas is a neighborhood of the city of Scandia in Washington County, Minnesota, United States. The Osceola and St Croix Valley Railway, which is part of the Minnesota Transportation Museum, goes through Copas. Minnesota State Highway 95 serves as a main route in the community. The John Copas House, built circa 1880 for the settler for whom the community was named, is listed on the National Register of Historic Places.

The Marine Mill, established in 1839, was the first commercial sawmill in what became the U.S. state of Minnesota. Now in ruins, it is currently a historic site managed by the city of Marine on St. Croix in partnership with the Minnesota Historical Society. It was listed on the National Register of Historic Places as the Marine Mill Site in 1970 for having state-level significance in the themes of exploration/settlement, industry, and transportation. It was nominated for being the birthplace of the region's seminal industry—lumbering—and a major landing on its crucial transportation route, the St. Croix River. The site is also a contributing property to the Marine on St. Croix Historic District.

The O'Brien Observatory (OBO) is an astronomical observatory in the city of Marine on St. Croix, Minnesota, United States, about 35 kilometers (22 mi) northeast of Minneapolis. The observatory is owned and operated by the University of Minnesota and opened in 1968. It has one telescope, a 0.76-meter (30 in) Cassegrain reflector capable of observing at both optical and infrared wavelengths. It is used for primarily for instruction and instrument testing, and occasionally for research purposes.

Scandia is a city in Washington County, Minnesota, United States. The population was 3,984 at the 2020 census. Scandia is 25 miles northeast of Saint Paul, Minnesota.

Gammelgården Museum of Scandia is an open-air museum in Scandia, Minnesota, United States. It is devoted to Swedish immigration history. The museum's mission is to preserve, present, and promote Swedish immigrant heritage. The museum receives around 5,000 visitors each year.

The Hay Lake School is a historic schoolhouse in Scandia, Minnesota, United States, in use from 1896 to 1963. It is now operated by the Washington County Historical Society as a museum alongside the 1868 Johannes Erickson House. The school was listed on the National Register of Historic Places in 1970 for having local significance in the themes of architecture, education, and social history. It was nominated as Scandia's first and only surviving early school.

The Johannes Erickson House is a historic log cabin in Scandia, Minnesota, United States, built in 1868 with a gambrel roof, a distinctive tradition from southern Sweden. It was moved to its current site adjacent to the Hay Lake School in 1974 to be part of a small museum complex operated by the Washington County Historical Society. The Erickson House was listed on the National Register of Historic Places in 1976 for having local significance in the themes of architecture and exploration/settlement. It was nominated as a rare surviving example of a style brought to Minnesota by Swedish immigrants from Dalsland and Småland.

Croixsyde is a historic house in May Township, Minnesota, United States, near the city of Stillwater. It was built from 1922 to 1927 as one of the first summer homes on the St. Croix River. It was listed on the National Register of Historic Places as the Benjamin B. Sheffield House in 1980 for its local significance in the themes of architecture and entertainment/recreation. It was nominated for being an early example of the area's summer homes and for its fine rustic architecture.

Square Lake is a lake in Washington County, in the U.S. state of Minnesota.Square Lake was so named on account of its boxy outline.

The Apple River is a 77.5-mile-long (124.7 km) tributary of the St. Croix River in northwestern Wisconsin in the United States. Via the St. Croix, it is part of the watershed of the Mississippi River. It issues from Staples Lake in Barron County and flows generally southwestwardly through Polk and St. Croix counties. In northern Polk County, it gathers the Fox Creek near White Ash Lake and traverses several lakes throughout its course. The river flows through the city of Amery and the villages of Star Prairie and Somerset. It joins the St. Croix River 7 miles (11 km) northeast of Stillwater, Minnesota. In the Ojibwe language, the Apple River is called Waabiziipiniikaan-ziibi, meaning "River Abundant with Swan Potatoes". This name was translated into French, but only pomme (apple) of the French word for "potato" (pomme de terre—"apple from the earth") was translated into English. The Apple River was once an important route of trade for the logging industry; timber was floated downstream from logging camps in the north to a sawmill in Amery, Wisconsin where it was cut, loaded onto trains and transported throughout the region. Today, the river generates tourism revenue through recreation and resorts, attracting 500,000 visitors a year. Its relatively gentle rapids make it very popular for canoeing, tubing, camping, concerts, and is a popular fishing spot through all seasons.

The Lee and Rose Warner Nature Center (WNC) was an outdoor education facility with a focus on natural history. It is located in Marine on St. Croix, Minnesota, northern Washington County about 30 miles (48 km) northeast of St. Paul, Minnesota. Warner was the first private nature center in the state of Minnesota. With funding from the Warner Foundation, at its closing WNC was the only nature center in the state of Minnesota to still provide free on-site programming to schools. On September 5, 2019, the Science Museum and Manitou Fund announced the Warner Nature Center would be closing, with operations winding down fully by December 31, 2019.