The largest city in the United States is, by far, New York. Philadelphia is the fifth largest. Separating them is New Jersey, the most densely populated state. Directly between New York and Philly — and all those people — there is a forest that has survived the bulldozers of development. The locals call this place the Sourland Mountain, or sometimes simply “the Sourlands.” SOURLANDS, the documentary, tells the story of this green oasis from the perspective of its remarkable citizens.