Wildlife Preserves' mission has always been to purchase and protect natural lands and wildlife as an intermediary for government acquisition for passive, natural uses, park preserves, and wildlife sanctuaries. Wildlife donated, sold, and in some cases its lands were taken to create many parks and preserves in New Jersey, New York, and as far north as Maine and New Hampshire. Some examples include Wildlife's contribution to the Great Swamp National Wildlife Refuge, the Sunken Forest National Park on Fire Island, Long Island, the Morris County Park's Willowwood Arboretum and Mahlon Dickerson Reservation, Division of Parks and Forestry land on Sparta Mountain, New Jersey Natural Lands Trust Great Piece Meadow Preserve, as well as other smaller contributions that expanded existing parks and preserves.
In its early years, Wildlife Preserves had envisioned a Passaic Valley National Wildlife Preserve, which has now become an impossible dream due to all the development that has gone on in and around the Passaic River Basin. The preserve was to include Black Meadows, Troy Meadows, and the Great Piece Meadows. Wildlife was able to save much of Troy Meadows in East Hanover and Parsippany - which it still owns - but Troy Meadows in Hanover was developed into the Algonquin Industrial Park and the Hanover Sewerage Treatment Plant. Black Meadows in Hanover is nearly all encumbered by the Morristown Airport with only about a third preserved by New Jersey Natural Lands Trust and the Township of Hanover. Little Piece Meadows was developed into industrial parks and the Willowbrook Mall, while a good portion of Great Piece Meadows was preserved by Wildlife Preserves and is now the Great Piece Meadow Preserve. Great Piece Meadows is split between the New Jersey Natural Land Trust and the Township of Fairfield, with some lots owned by the Fairfield Conservation and Sportsman's Association and a few private owners. The Great Piece Meadow Preserve is managed by Wildlife Preserves, New Jersey Natural Land Trust, and Fairfield Township.