Mills Reservation is a 157.15-acre county park on First Watchung Mountain in Cedar Grove and Montclair, New Jersey, preserving forest, grassland, cliffs, and broad views from Quarry Point across Newark, the Hudson River, Manhattan, and the New York City skyline. The land was once shaped by quarrying, including steam-powered rock blasting from 1890 to 1918. In 1952, David and Ella Mills bought 118 acres to save the site and gave it to Essex County, after which the Olmsted Brothers designed the park. Today it is valued for quiet foot travel, birdwatching, and hawk migration observation, while Quarry Point also retains traces of wartime and older signaling traditions.