Slated with a 1956 completion date, the first from the Northern State to NY 25 (Jericho Turnpike) opened on November 29, 1954, with the landscaping at NY 25 incomplete. The LISPC believed that Sunken Meadow State Park, when the parkway was finished, was to become the second-most used park on Long Island, behind Jones Beach State Park. On April 1, 1957, the Long Island Parks Commission opened the full alignment of the Sunken Meadow State Parkway to traffic, after an $11 million (1957 USD) construction project on the .