Mount Haystack is the third highest peak in the state of New York at 4960 feet, after Algonquin Peak and Mount Marcy. It gets its name from the resemblance of its rounded, conical peak to a haystack. Despite this and the views offered from its bare, alpine summit, it is not visited by as many hikers outside of aspiring members of the Adirondack Forty-Sixers; it is rather remote from the nearest trailhead and the approach from either direction is steep and challenging.

The most frequent approach if Haystack is the main goal is to follow the Johns Brook Trail from the popular Garden parking area in Keene Valley to the Phelps Trail and then use Shorey's Short Cut to get over to the Range Trail. This route is a 7.8 mile one way hike with an elevation gain of just over 4000 feet.  It is possible to combine this with an attempt on Marcy itself, but that makes for a long day and the approach from Panther Gorge is even steeper than that from the north.

Some hikers come along the Great Range itself, making the peak their last stop before Marcy itself, or combine it with neighboring Basin and Saddleback. It can also be approached from privately-owned Upper Ausable Lake.

One of the most famous elements of Haystack is the infamous "Devil's Half Mile". This stretch, which is technically three-fourths of a mile, is the extremely steep last stretch of the trail.