Prior to becoming a park, the land was used as part of the coastal defense system for New York City during World War II.

After the previous owners won approval to subdivide their property into several residential lots, preservation efforts intensified.

[1][2] The park is largely undeveloped, and has no infrastructure beyond elevated platforms for birdwatching and trails for hiking, biking, and cross-country skiing.

[1] Shadmoor State Park derives its name from the thick shadbush (Amelanchier) found growing atop the bluffs.

Also found growing in the park are black cherry trees (Prunus serotina) and the endangered sandplain gerardia (Agalinis acuta).