[4] On its east the slopes drop generally steeply down to Big Indian Hollow, the valley of the headwaters of Esopus Creek, around 1,200 feet (370 m) above sea level.

Tributaries and subtributaries of the Esopus drain even steeper valleys radiating out in a fan-shaped pattern from Lost Clove at the northeast to McKenley (also McKinley) Hollow in the southeast.

A narrow valley carries the combined streams down to Dry Brook, a tributary of the East Branch of the Delaware River.

[7] Later glaciation, primarily the Illinois and Wisconsin periods, shaped the slopes of the mountain, making them even steeper and gradually forming Esopus Creek from its meltwater.

The rocks of the stream are fractured and faulted much more than elsewhere in the Catskills, and it and its tributary Woodland Creek make an almost complete circle around the mountain, a rosette pattern similarly unusual in the region.

Yngvar Isachsen of the New York State Geological Survey has found evidence strongly suggesting that the entire Panther Mountain region is the inverse form of a crater that formed after an ancient meteor impact when the Catskills were a river delta at the northeastern corner of the inland sea that is now the Allegheny Plateau.

Northern hardwoods, primarily beech, birch and maple species, predominate, with some occasional cherry and mountain ash.

[9] Southern species such as oaks, isolated American chestnuts that survived the blight, shagbark hickory and dogwoods are located close to streams near the base.

On the mountain's summit, boreal species such as balsam fir and red spruce make an appearance, forming some small stands but not a continuous cover as is seen on higher peaks in the range.

Around 1970, Catskill forest historian Michael Kudish found the few remaining trees in a fir stand at 3,150 feet (960 m) on the north slope; these have since all died due to heavy deer browse.

The sole exception is 2,940 feet (900 m) on the north slope, where the absence old sugar maples and the presence of white ash are signs that a small area along the ridgeline was logged at some point in the past.

[14] Small farms were established on the mountain's lower slopes; as late as 1900 the U.S. Geological Survey quadrangle maps of the area show a road going up the ridge between Lost Clove and McKenley Hollow to a structure called Platt's Cabin just below 2,500 feet (760 m).

This committed the state Department of Environmental Conservation (DEC) to manage the land with the goal of minimizing human impact as much as possible.

Accordingly, the lower of the two McKenley Hollow lean-tos was removed as it had become a site for parties[16] due to its proximity to the trailhead and parking lot on that side.

[18] From the junction, the blue-blazed Pine Hill-West Branch Trail ascends the final 570 feet (170 m) moderately up the 0.75 miles (1.21 km) to the summit.

Just below the summit a sign at 3,500 feet (1,100 m) advises hikers of special DEC regulations allowing camping above that elevation only in wintertime, and prohibiting open fires.

In the saddle between the two summits a small ledge allows for views to the northwest over the hamlet of Big Indian with West Kill, Hunter and Plateau mountains, all High Peaks, beyond.

[17] The southern terminus of the trail is near Frost Valley YMCA along County Route 47, 9.9 miles (15.9 km) away, and entails climbing Big Indian, Eagle and Haynes mountains before Balsam.