The main trail begins at the Cache La Poudre river on the Poudre Canyon Highway about 30 minutes from Fort Collins. After about .75 miles the trail splits. To go left on Greyrock Meadows trail adds 2 miles to your trip and provides excellent views of Greyrock Mountain and Meadows from the south, eventually connecting back with Greyrock Mountain trail. Going right on Greyrock Mountain Trail takes you directly up the gulch to the base of Greyrock.

From either direction, follow the trail till you reach the base of Greyrock, taking it around to the north side. On the north side it's easy to lose the trail and end on a dead-end ledge on the east side. Be sure to contour around to the north until the trail becomes apparent. There are signs.

Keep heading south across the meadow and over the large slabs of granite past a large pool until the obvious summit on the south end is gained.

In 2004 a 9,000 acre forest filed called the "Picnic Rock Fire" decimated the area. Geologically, Greyrock Mountain is a visible outcropping of the Log Cabin Batholith, a glacier-eroded igneous intrusion into the overlying gneiss and schist of slightly-pink Silver Plume Granite that formed over 1.4 billion years ago.