O'Leary Lookout

Sunset Crater from O'Leary Peak

10 miles round trip, 2050 feet elevation gain
Difficulty: Moderate
Access: Paved road to trailhead, no entrance fee required

O'Leary Lookout offers a view, both expansive and intimate, of the Painted Desert and the San Francisco Volcanic Field of northern Arizona. The peak offers a chance to peer down into nearby Sunset Crater with beautiful views of the snowcapped San Francisco Peaks and faraway views of the Grand Canyon and Navajo Mountain. Although the trail itself may be boring, following a gravel road still used by the Forest Service to access the lookout, the views along the trail and at the summit more than justify O'Leary as a worthy destination. This is a hearty northern Arizona hike that allows you to enjoy the non-Grand Canyon features of this part of the state.

I hiked up to O'Leary Lookout on a pleasant winter day during a year with remarkably little snow in the Flagstaff area. Hoping to catch early morning light on the landscape of the Colorado Plateau and the Painted Desert, I chose to hike this trail very early, starting over an hour before sunrise; this meant that I was up and back down the mountain by 11 AM. I drove to the trailhead from Flagstaff in the dark; I followed US 89 north out of Flagstaff. After driving up the first major hill north of Flagstaff, I turned right onto Route 395, following signs for Sunset Crater National Monument and Wupatki National Monument. I followed this road two miles to reach Bonito Park, a wide, grassy meadow with views of Sunset Crater ahead and the San Francisco Peaks to the west. At the eastern end of the Bonito Park, I took the turnoff for the O'Leary Campground on the left (north) side of the road. I followed this road to a point where it made a sharp left turn into the campground; here, I went straight and parked in a small parking area next to a locked gate. As the trailhead is in Coconino National Forest rather than Sunset Crater National Monument, no entrance fee is required to hike here.

As I hiked up in the dark, I'll describe sights that I saw on my descent. The first mile of the trail- which was really a road- was essentially flat, with a slight bit of elevation loss in the very beginning as the trail approached the Bonito Lava Flow. Shortly after leaving the trailhead, the trail began to parallel the edge of the Bonito Lava Flow. Even 900 years after the eruption of Sunset Crater, the lava flow is able to support only some vegetation: while some trees have sprouted up in the dense field of a'a lava. The lava flow boundary was abrupt; on one side, ponderosa pines grew in ash-dense soils, on the other side, fragmented, hardened black lava stifled most vegetation from sprouting.

Sunset Crater, Bonito Lava Flow

The two summits of O'Leary Peak rose ahead, with the fire lookout prominently sticking out on the mountain's south summit. O'Leary Peak, like all of the nearby peaks, is of volcanic origin, with the same geological origins as the other cones of the San Francisco Volcanic Field. However, unlike Sunset Crater, which is a cinder cone, and Mount Humphreys, which is a remnant of a stratovolcano, O'Leary Peak is a lava dome- it's made up mainly of viscous lava that piled up to form a mountain.

O'Leary Peak

After a mile of flat hiking, the trail began to ascend as it reached the foot of O'Leary Peak. The initial ascent was direct, with no switchbacks, but as the slope of O'Leary Peak became steeper, the trail/road began using switchbacks for the ascent. The wide trail was easy to follow and grades along the trail, with the exception of the very end, were generally reasonable as the road is still used by Forest Service employees to access the fire lookout at the summit. At 2.3 miles from the trailhead, the trail made a switchback to the east just downhill from a saddle.

Road/trail

At this point, the road emerged into the first views of the hike. Sunset Crater and a number of other small volcanic cones were visible across the mostly-desolate flat plain of the Bonito Lava Flow.

Sunset Crater and the Bonito Lava Flow from the trail

The eastward switchback was the longest switchback of the hike, at over a mile long; over the course of this switchback, the trail recorded a fairly substantial elevation gain, though all at a reasonable grade. At the end of the switchback, the trail arrived at a high saddle between O'Leary Peak and Darton Dome. Along this switchback, good views of the San Francisco Peaks emerged to the west. From this vantage point, I was able to gaze directly into the Inner Basin of the San Francisco Peaks. This valley is actually a caldera- the San Francisco Peaks are the remnant of what used to be a massive stratovolcano. The northeast face of the mountain eventually collapsed in an eruption likely similar but larger than the eruption at Mount St. Helens in 1980. Arizona's highest peaks- Mount Humphreys and Mount Agassiz- are simply high points along the caldera of what was once a much greater volcano.

After the long switchback, the trail/road continued ascending via switchbacks for another mile and a half to reach the summit. At this point, the sun rose and I caught beautiful sunrise lighting on the San Francisco Peaks.

Sunrise on the San Francisco Peaks

As the trail winded up the mountain, the north and main summit of O'Leary Peak came into view. After the trail reached a saddle between the peaks, it aimed for the south summit, which was only a few feet lower than the north summit. The final stretch of trail was very steep and featured metal grating over the road to provide more traction for trucks ascending to the lookout. At the end of the steep stretch, I arrived at the summit, which was topped by a tall fire lookout tower which stuck out above the tree line. The summit itself was mostly surrounded by trees.

O'Leary Lookout

The lookout cabin itself was closed when I visited, but by exploring around the summit and lookout area, I was able to piece together a panoramic view of the entire area. The best viewpoint was a few steps past the lookout atop a jumble of boulders facing the south. That spot provided a sweeping view of Sunset Crater and the San Francisco Peaks.

San Francisco Peaks from O'Leary Lookout

The San Francisco Peaks were initially named the Sierra Sin Agua by the Spanish for the dry climate in the area (Sin Agua translates to "without water"), ironic as nearby Hopi and Yavapai peoples found the mountains to be a rare lush spot in an otherwise harsh and dry landscape. The Sin Agua name was later applied to the precontact peoples who lived in the Flagstaff and Sedona areas who built elaborate pueblos that were abandoned by the time of European colonization.

To the south, I could look down into Sunset Crater. Snow coated the northern slopes of the crater and the morning sunlight kissed the cinder cone's colorful rim. John Wesley Powell, the legendary one-armed explorer of the Southwest, named the volcano for the red cinders near its summit crater. Sunset Crater was formed in one largely continuous burst of volcanic activity around AD 1080. Its formation was likely similar to that of Mexico's Paricutin: a volcanic vent spewing cinders and ash erupted from a previously peaceful spot, with a continuous eruption that eventually built up a cinder cone 1000 feet high. The eruption was accompanied by a lava flow of a'a lava from the vent that spilled to the west, filling a plain and creating the Bonito Lava Flow. Archaeologists have found evidence that the Sinagua people once inhabited this area; Sunset Crater's eruption forced their departure either south to Walnut Canyon or north to Wupatki.

Sunset Crater and the Bonito Lava Flow from O'Leary Peak

Sunset Crater is actually just the latest volcano to erupt in the San Francisco Volcanic Field, which contains some 600 volcanoes. Spread out on an east-west axis north of Flagstaff, the San Francisco Volcanic Field is likely the result of a subcrustal hotspot; activity in the field has appeared to migrate from west to east over the millions of years of activity in the field. The field is also responsible for the former stratovolcano at Humphreys Peak and for the field of cinder cones visible in all directions from the summit of O'Leary Peak. In fact, O'Leary Peak's lava dome is itself a creation of the San Francisco Volcanic Field as well.

The North Rim of the Grand Canyon and cinder cones of the San Francisco Volcanic Field

The north rim of the Grand Canyon was also visible to the northwest past a line of especially shapely cinder cones. Navajo Mountain, a massive mountain in Utah near the Glen Canyon, was visible to the north past the canyons of the Little Colorado River. Doney Crater and the landscape of Wupatki was visible to the north as well, although I was unable to spot any of the pueblos despite my best efforts. To the east was the vast expanse of the Painted Desert, a mostly flat landscape punctuated by occasional buttes and canyons. To the southeast, past Sunset Crater, I spotted what appeared to be the circular rim of Meteor Crater, another incredible Arizona geological feature formed about 50,000 years ago by a meteorite impact.

Painted Desert

The popularity of this trail is unclear to me. On a nice but cold January morning (the temperature was 14 F outside when I began hiking), I saw one other hiker; Flagstaff is a very outdoorsy town and the views at O'Leary were nice so I'd be surprised if the peak is consistently overlooked. The trail is also mentioned occasionally in National Park Service literature at Sunset Crater Volcano National Monument, though I doubt few visitors to the monument would bother hiking up to O'Leary. In any case, as I had the summit to myself for an hour, it's clear that there are certainly times when one can find solitude on O'Leary Peak.