Its hiking trails traverse rolling glacial moraine, riparian zones, restored oak savanna, wooded areas and bogs.

It is a popular place for birdwatching, picnics, camping, cross-country skiing, canoeing, fishing, and other typical outdoor recreational activities.

This park is home to raccoons, white-tailed deer, foxes, minks, beavers and woodchucks.

In 1945, 20 years after William O'Brien's death, his daughter Alice offered 180 acres (0.73 km2) along the riverfront to the state.

Land was added to the park at every opportunity, to reduce crowding and to prevent housing developments from being built right up to the boundary.