The Bortle Scale rates nighttime skies according to their celestial-body visibility, with a score of 9 for maximum light pollution and a 1 for inky blackness. While the East Coast averages a 7 (from space, it resembles the Vegas strip), northern Pennsylvania's Cherry Springs State Park scores a remarkably dark 2. The park's nearly flawless darkness is due to its perch: 2,300 feet atop the Allegheny Mountains. The 82-acre park is also 60 miles from the nearest city and surrounded by 262,000 acres of forest that shields residual glow. Go during a new moon, and pitch your tent in the northeast corner of the park's 48-acre stargazing field, where the scene is most expansive – at times the Milky Way is so bright it casts a shadow on the grass.
Getting there: From the Bradford Regional Airport, drive an hour on Highway 6 to Cherry Springs State Park. You can then make a reservation to stargaze overnight at the Astronomy Observation Field, which runs $11 for the first night.