Big Stone Lake is 30 miles long and is located on the South Dakota-Minnesota border. The lake is the source of the Minnesota River and attracts anglers who catch walleye, northerns and bluegills. The northern section of the park, called the Bonanza Area, provides a picnic area, boat launch and a primitive group camp for guests. The area also includes the Big Stone Lake Environmental Education Center which provides a place to discover the past and ways to preserve it. The southern section of the park, called the Meadowbrook Area, contains a campground, swimming beach and hiking trails.

Big Stone Lake State Park is part of the Minnesota River Country Landscape Region, a large area which extends almost 200 miles from Ortonville to Mankato. At one time, the landscape consisted of tall and mid-grass prairie, interspersed with marshes, lakes and streams. Today, extensive farming has replaced the prairie. Cottonwoods, ash, and silver maples can be found on the lake's shoreline. The Bonanza Area includes 30 acres of rare glacial till hill prairie, which is designated as a Scientific and Natural Area (SNA).

Long ago, this area was the south end of glacial Lake Agassiz. Torrents of water cut the valley when glacial river Warren drained Lake Aggassiz. The area around Big Stone Lake State Park consists of granite and gneiss quarries. The top three inches of stone is exposed and contains the fossil remains of sharks' teeth.

Deer, raccoons, thirteen-lined ground squirrels, meadowlarks, sedge wrens, robins, thrashers and mourning doves are sighted in the park.

In 1923, State Auditor Ray Chase critiqued the state park system and thought there was a geographic imbalance in the system. In his proposal for additional parks, Chase urged that more state parks be established in southern Minnesota. The Ortonville area was targeted as a place with a need for a state park. It wasn't until 1961 that Big Stone Lake State Park was established at the urging of Ortonville business people who were concerned about lakeshore development. Working with U.W. (Judge) Hella, director of Parks and Recreation Division, legislation was drafted to establish Big Stone Lake as a state park.