 DuPont donated 1,234 acres to Pennsylvania and 528 acres to Delaware to form the bi-state White Clay Creek Preserve.In 1988, the heirs of S. Hallock du Pont announced they were planning to sell off 850 of the estate's 2,000 acres, which had been held in trust for future generations.Seeking to limit the loss of open space, Governor Michael Castle began the purchase of 321 acres of the land which would connect Walter Carpenter State Park and the White Clay Creek Preserve to the Middle Run Valley Natural Area, a county-run park.