[3] Sandy Creek, the stream that was dammed to create Lake Wilhelm, was noted in reports made by George Washington during his 1753 trip to Fort LeBoeuf during the French and Indian War.

Plans were delayed by the start of World War II but the citizens of Mercer County could see the benefit of building a flood control dam on Sandy Creek.

Migrating waterfowl like the loon, common teal, goldeneye, merganser, and bufflehead stop by Lake Wilhelm in the spring and fall.

Bluebirds and purple martins make their homes in the old fields and meadows of Maurice K. Goddard State Park.

Common game fish found in the lake include largemouth and smallmouth bass, perch, crappie, bluegill, catfish, walleye, northern pike and muskellunge.

[2] The portions of Lake Wilhelm that are within Maurice K. Goddard State Park are open to watercraft up to 20 horsepower (15 kW).

All vessels must have current registration from any state or a launch permit from the Pennsylvania Fish and Boat Commission.

[4] The Friends group also organizes two big events for the park: the Pioneer Frolic and Music at the Marina.

The Pioneer Frolic takes place the last weekend in June and includes reenactors, food vendors, live music, and other entertainment.

Music at the Marina showcases local bands and independent musicians with the addition of food vendors, a car cruise, and fireworks.