While only the northeastern quadrant and summit are part of the recently created Schunnemunk State Park,[3] some popular hiking trails and access routes have long crossed the privately owned lands elsewhere on the mountain.

Along the more northerly of its length, the mountain has a double crest, with Barton Swamp lying between the two ridges.

The New York State Thruway runs alongside Schunemunk's eastern side for the length of the mountain just north of its Harriman exit.

Schunemunk is geologically dissimilar from nearby mountains in the Hudson Highlands, being formed from sedimentary deposits including conglomerate.

The Dark Hollow, Barton Swamp, Trestle, Western Ridge, and Otterkill trails are also located on the mountain.

On May 22, 2002, a group of hikers was bushwhacking on a boulder field on the southeastern side of the mountain, above Dark Hollow Brook.

Nicholas Styranovski of Astoria, NY had passed the boulder field and gone back to help some of his fellow hikers who were less steady at about noon on May 22, state police said.

The field was part of a pre-existing rock slide where boulders came to rest after falling down a steeper slope, said Edward Goodell, the executive director of the New York-New Jersey Trail Conference, an organization that helps maintain the area's hiking paths.