Acadia National Park, Maine
Acadia National Park is home to Cadillac Mountain, which is the highest point in the east coast. For $10-20 depending on the time of year when you visit, you can make camp in either of the two campgrounds: Blackwoods and Seawall. It cost $20 per vehicle to enter the park or you can buy an annual pass for $40. The park is open year round.