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Blue Mountain (Pennsylvania) facts for kids

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Blue Mountain
The "Great Wall" of Blue Mountain
Highest point
Peak Clarks Knob
Elevation 2,320 ft (710 m)
Coordinates 40°3′0″N 77°44′52″W / 40.05000°N 77.74778°W / 40.05000; -77.74778Coordinates: 40°3′0″N 77°44′52″W / 40.05000°N 77.74778°W / 40.05000; -77.74778
Length 150 mi (240 km) east-west
Country United States
State Pennsylvania
Borders on Ridge-and-Valley Appalachians and Great Appalachian Valley
Period Silurian
Type of rock Tuscarora Formation and Shawangunk Formation; sedimentary

Blue Mountain is a ridge that forms the eastern edge of the Appalachian mountain range in the U.S. state of Pennsylvania. It cuts across the eastern half of the state from New Jersey to Maryland, providing a distinct boundary between a number of Pennsylvania's geographical and cultural regions. To its northwest side are the southern and central mountains and valleys, the "coal region," and the Poconos. To its southeast side are the Cumberland Valley, the "capital region," Lebanon Valley, Pennsylvania Dutch Country, and the Lehigh Valley.


The ridge of Blue Mountain runs for 150 miles (240 km) through Pennsylvania, reaching an elevation of 2,270 feet (690 m) above sea level just north of the Pennsylvania Turnpike, near the borough of Newburg. Most of the ridgecrest, however, only reaches between 1,400 feet (430 m) and 1,700 feet (520 m) in elevation. The mountain's width varies from 1 mile (1.6 km) to 3 miles (4.8 km).

The southwestern end of the mountain is at Big Gap, west of Shippensburg. (The mountain ridge continues to the southwest towards Maryland under the name of Broad Mountain.) The northeastern end of the mountain is at the Delaware Water Gap on the New Jersey border. Mount Minsi forms the promontory overlooking the Delaware River. The ridge of Blue Mountain continues northeast into New Jersey as Kittatinny Mountain.

Blue Mountain marks the boundary between the Great Appalachian Valley and the main Ridge-and-valley Appalachians.

Water gaps

Four of Pennsylvania's major rivers cut through Blue Mountain in water gaps.

The Pennsylvania Turnpike

Blue Mountain Tunnel portal
The western portal of the eastbound Blue Mountain Tunnel.

The Pennsylvania Turnpike system passes through the Blue Mountain at two points.

  • The Blue Mountain Tunnel carries the Turnpike's east-west mainline (Interstate 76) through the ridge in northern Franklin County. The Kittatinny Mountain Tunnel bores through a parallel ridge of the same mountain just to the west, with the two tunnel portals only 0.2 miles (0.32 km) apart.
  • The Lehigh Tunnel, so named to avoid confusion with the former, carries the Turnpike's north-south Northeast Extension (Interstate 476) through the ridge between Lehigh and Carbon Counties.

Both tunnels (each consisting of two tubes) carry two lanes in each direction of travel.

Blue Mountain attractions in Pennsylvania

Blue Mountain School District is named after the mountain range. It is located just off Rt. 61 in Schuylkill Haven, Pennsylvania.

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