The earliest recorded ascent was made by Ed Phelps and Thomas P. Wickes in 1875.

The Phelps Trail begins at the Garden Parking Lot in Keene Valley on New York State Route 73.

The ADK Range Trail branches off at a DEC Interior Outpost located 3.1 miles (5.0 km) from the trailhead.

The trail to the right goes over Upper Wolfjaw and continues to the summit of Armstrong, 3.9 miles (6.3 km) from the DEC Interior Outpost, for a total one-way distance of 7.0 miles (11.3 km) and elevation gain of 2,500 feet (760 m).

The summit offers views of Johns Brook Valley and the other peaks of the Great Range.