Overview
The Wilderness of Rocks is one of the most striking landscapes in Coronado National Forest, a plateau of tumbled granite boulders and open meadows between 8,000 and 9,000 feet in the Santa Catalina Mountains. The route to Mt. Lemmon through this area combines the dramatic rock scenery of the wilderness with the forested summit environment of the highest point in the Catalinas, making it the most complete big-day hike in the range.
The Catalina Highway at the trailhead sits at roughly 6,000 feet near Summerhaven, reducing the effective starting elevation but still requiring significant climbing to reach the summit.
The Route
Miles 0.0 to 2.0: Marshall Gulch to Wilderness Entry
The trail begins at the Marshall Gulch picnic area and follows the creek drainage upstream through mixed conifer forest. The grade is moderate. At mile 2.0 the trail enters the Wilderness of Rocks area as the forest opens into boulder-strewn meadows.
Miles 2.0 to 5.0: Wilderness of Rocks Traverse
The trail winds through the granite landscape, climbing past massive boulders and through meadow clearings. Views of the desert far below appear frequently. The route requires some navigation attention as social trails branch in multiple directions through the rock garden.
Miles 5.0 to 6.0: Summit Approach
Above the Wilderness of Rocks the trail climbs into the spruce-fir zone characteristic of the summit area. At 9,157 feet, Mt. Lemmon is the terminus of the life zone transect that begins in saguaro cactus desert at the mountain's base.
Miles 6.0 to 12.0: Return
Descend the same route. The descent through the Wilderness of Rocks is enjoyable in the opposite direction.
When to Hike
April through June is ideal before summer heat and monsoon season. Snow may linger in the upper sections into April.
September through October provides the best fall conditions with clear skies and comfortable temperatures.
July through August is monsoon season. Start early (before 7 AM) and aim to be off exposed terrain before noon.
November through March the upper sections may have snow. The Wilderness of Rocks area can be icy; microspikes are recommended from November through March.
What to Bring
Many hikers carry 3 liters of water for this long route. Marshall Gulch creek can be filtered at the start. The summit area can be significantly cooler and windier than the trailhead; carry a warm layer. Sun protection is essential throughout, particularly in the open Wilderness of Rocks section. Start early to build in turnaround flexibility.
Trailhead Access
Marshall Gulch picnic area is located on the Catalina Highway approximately 25 miles from Tucson. A recreation fee of $10/vehicle is required for entry to the Santa Catalina Recreation Area (as of 2026). The America the Beautiful Pass covers this fee. Vault toilets at the picnic area. Dogs must be leashed in the picnic area.
Nearby
Butterfly Trail departs from a nearby trailhead along the Catalina Highway and provides a shorter high-elevation alternative. Sabino Canyon to Seven Falls accesses the mountains from the southern base through Sabino Canyon.
Before attempting this strenuous route, check weather, lightning forecasts, and trail conditions at checking conditions before you go. Lightning in the Wilderness of Rocks during monsoon season is a serious risk. Practice Leave No Trace principles throughout.