Pennsylvania

The Pennsylvania part of Wills Mountain is in Bedford County, reaching an elevation of 2,782 feet (848 m). Although there are mountains in Pennsylvania's Appalachian Plateau that are higher, Wills Mountain is the highest in its Ridge and Valley physiographic province. Wills Mountain may have the highest prominence in Pennsylvania. The mountain ridge begins abruptly near the Juniata River just north of 2,560-foot (780 m) Kinton Knob, west of Bedford, and just south of the Pennsylvania Turnpike. The valley to the south of Kinton Knob is known as Milligans Cove, an excellent geological example of a breached anticline.

Portions of Wills Mountain, including the summit, are located in Pennsylvania State Game Lands No. 48, where access to the mountain is limited, with only jeep trails and a gravel road on the ridge. The summit, like Martin Hill to the east, has no towers or transmitters. However, access to the summit is difficult, requiring a hike of more than 1,800 ft (550 m).

Maryland

Cumberland Narrows west of Cumberland, Maryland, the water gap along Wills Creek through which the National Road crosses between Haystack Mountain (left) and Wills Mountain (right). This is the passage through the rugged Wills Mountain Anticline now used by the Western Maryland Scenic Railroad (left), Alternate U.S. Route 40 (center, left of the creek), and the CSX Railroad (right).

The Maryland part of Wills Mountain is located in Allegany County, where the mountain rises steeply from the Cumberland Narrows, a water gap west of Cumberland, half a mile (0.8 km) west of the mouth of Warrior Run. From there, the mountain extends northeasterly into Pennsylvania; the mountain's highest elevation in Maryland is 1,877 feet (572 m).

Haystack Mountain is on the south side of the Narrows. Geologically, the two mountains are equivalent, both being central ridges of the Wills Mountain Anticline. The Cumberland Narrows was carved into these quartzite-capped mountain ridges by Wills Creek, a Potomac River tributary, over millions of years.

The Cumberland Narrows serves as a western gateway from Cumberland to the Appalachian Plateau and the Ohio River Valley beyond. The Old National Road, now Alternate U.S. 40, passes through the Narrows, along with the former Baltimore and Ohio Railroad's main line between Baltimore/Washington and Pittsburgh, now part of the CSX system, and a former line of the Western Maryland Railroad, now used by the steam- and diesel-powered excursion trains of the Western Maryland Scenic Railroad and the Great Allegheny Passage bike trail.

A prominent rocky outcropping at the south end of Wills Mountain in the Cumberland Narrows is known as Lover's Leap.