Mount Ajo

Mount Ajo 4808′

Organ Pipe Cactus National Monument

Total Time: 4:45

Roundtrip Mileage: 8.2 miles

Elevation Gain: 3050′

Crux: Class II-III

Trailhead: Bull Pasture Trail


Mount Ajo is the crown jewel of Organ Pipe National Monument. The highest summit in the park, Ajo rises 4000′ above the desert just a few miles north of the border with Mexico. My particular interest in the summit stemmed from its inclusion on both the Sierra Club’s Desert Peak Section (DPS) List, as well as being one of Arizona’s 73 summits with over 2000′ of prominence. Following a grueling cross country climb up Kino Peak that morning, the plan was to tag Ajo in the afternoon for a late return to Phoenix. Hardly a novel plan to climb both Organ Pipe DPS Peaks in the same day, it would still make for a very full outing. I was pleased with my time on Kino- taking 6 hours for the elaborate cross country route, but underestimated how long it would take me to reach the trailhead for Ajo. By the time I drove the 20 miles of dirt road back to Route 85, headed south to the Organ Pipe Visitor Center to refill water, then drive another 14 miles of dirt road to the Bull Pasture Trailhead, I had burned a good 2 hours and it was already 3PM. Starting out, I was fairly sure I would be finishing the hike in the dark, not an ideal prospect being so close to the border. But unlike Kino Peak, this portion of the park is very popular and the terrain less conducive to illegal trafficking through the area, the trail mostly following northern slopes that would require some steep, loose bushwacking from the south, with much easier routes north around the range for those on foot. There were a number of cars at the trailhead when I arrived, and I shouldered my pack and headed up the well defined trail.

From the trailhead.

I shortly passed the junction for the trail into Estes Canyon (which can be used to make a nice loop hike) and headed up the switchbacks towards bull pasture. The trail generally follows the SW ridgeline, skirting below various cliff bands and pinnacles en route. I reached Bull Pasture at about the 2 mile mark and found two people admiring the view on a bench, the last hikers I would see all day. The Bull Pasture area is a desert version of an alpine meadow with grasses and wildflowers taking advantage of the cooler northern slopes.

Bull Pasture
The cliffs above Estes Canyon.

Although the official NPS trail ends at the edge of the pasture, a very obvious trail continues on towards the summit of Mount Ajo. I continued along skirting additional cliffs and pinnacles as the trail began to climb more aggressively up a steep side canyon to gain the main southern ridge. A combination of dehydration and fatigue from the earlier start from Phoenix and subsequent climb of Kino Peak dramatically slowed my progress, and it took me far too long ascend the to where the trail finally meets the ridgeline shortly before a huge false summit.

Ascending a side canyon.
Nearing the ridgeline with the false summit straight ahead.

I had been dreading the false summit for nearly the entire climb, and was pleased to find the trail skirted it to the east instead of climbing up and over it directly, bringing me to the level of the saddle between the false and true summit without any wasted climbing. From the saddle, it was a short 5 minute hike and scramble up the only bit of class 3 for the climb. The benchmark and summit register were on the south side of the summit rocks, but the spot just north of a small radio tower appeared a bit higher. I walked around until I was content that I had tagged the highpoint, and took a few photographs in each direction.

View north across the range.
View to the SE, Baboquivari in the distance.
Summit panorama to the East.
View south into Mexico.

Despite being both farther south and west of Phoenix, I still only had about an hour of sunlight left, and couldn’t afford to spend much time soaking in the the views. With gravity on my side, I half jogged down the trail with hopes of at least making it to Bull Pasture before dark. The sun dipped below the horizon just as I reached the steep canyon and hooked west, and I just made it to Bull Pasture when I put on my headlamp.

Sonoran sunset.

The trail was tricky to follow in the dark and I lost it briefly just before the bench at the start of the formal NPS trail, but was able to refind it with help of my GPS. Skirting the cliffs on my descent, twilight changed to darkness, and the darkness won over logic, as my mind wandered to impending attacks from Desperadoes at any moment. Of course, I made it back to my car without incident. Driving out along the dirt loop road back to Route 85, I passed a number of Border Patrol cars stationed at various pullouts along the way. I couldn’t help but wonder if I had been tracked during my climb….. From there, it was a nearly 3 hour drive back to Phoenix with two more DPS peaks ticked off the list.

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