Sheldon Marsh State Nature Preserve, formally known as Sheldon’s Folly, was owned by Dr. Dean Sheldon from 1954 to 1979. A Sandusky obstetrician and conservationist, Dr. Sheldon bought the 56 acres from Cedar Point, which included the original entrance and roadway to the amusement park.
Dr. Sheldon built a cabin as a family retreat, but otherwise did little to develop the wetlands beyond adding ponds and plantings to provide food and shelter for wildlife. He often opened the area to visitors, including Boy Scouts, Girl Scouts, schools and other youth groups.
The State of Ohio purchased Sheldon's retreat in 1979 from his estate, adding another 330 acres of marsh and barrier beach to the property and dedicating it as a nature preserve the next year. Grants helped the state later add another 75 acres to the preserve.