- Arizona County HP: #13
- Difficulty: ⭐️⭐️ 1/2 (on a scale of 4)
- Summit Elevation: 10,709 feet
- Mountain Range: Pinaleño Mountains
- Ancestral Lands: Western Apache, Chiricahua
PLANNING DETAILS
Location: Mount Graham is located in the Coronado National Forest, approximately 70 miles northeast of Tucson. The closest town with amenities is Safford, AZ.
When to Visit: Late Spring to Fall. Mount Graham is Arizona’s most prominent mountain (and the 20th most prominent mountain in the U.S.). The Swift Trail Parkway (AZ Highway 366) leads visitors up to an elevation of 9,000 feet on the mountain. However, because of the road’s very tight curves, the Arizona Department of Transportation closes access during the winter months. Visitors can check the road’s closure/re-opening status online at AZ 511.
Fees/Permits Required: Mount Graham’s summit sits inside the Mount Graham Red Squirrel Refugium. The refugium was established to protect an endangered squirrel subspecies that only lives in the high-elevation conifer forests of the Pinaleño Mountains. The top of Mt. Graham is closed to the public to protect its habitat and promote red squirrel repopulation.
Getting There: Visitors must approach Mount Graham using the Swift Trail Parkway (AZ-366), which begins on the mountain’s eastern side near Safford, AZ.
Directions from Tucson: Follow I-10 east for 98 miles. Take Exit 352 (US-191) toward Safford, and follow US-191 north for 26 miles. Turn left onto AZ-366 toward Mount Graham and follow the Swift Trail Parkway west for 22 miles. The dirt road leading to Mount Graham’s summit is located where the pavement ends.
Directions from Phoenix: Follow I-10 east toward Tempe/Mesa. Take Exit 154 (US-60) toward Globe. Follow US-60 for 80 miles. At the east end of Globe, continue straight onto US-70 and follow US-70 east for 76 miles toward Safford. In Safford, turn right onto US-191 and follow it south for 7.6 miles. Then turn right onto AZ-366 toward Mount Graham and follow the Swift Trail Parkway (AZ-366) west for 22 miles. The dirt road leading to Mount Graham’s summit is located where the pavement ends.
Parking: Because Mt. Graham’s summit is closed to the public, there is no dedicated parking area for this high point. There is room for 5-6 cars to park near a pullout where the pavement ends on Swift Trail Parkway. A dirt road up to the red squirrel refugium heads uphill from this parking area.
Pets Allowed: Pets are permitted on the first 1.7 miles of this hike up to the boundary sign for the red squirrel refugium.
Kid Friendly: Reaching this summit requires trespassing. A more kid-friendly hike is the nearby Heliograph Peak Trail, which begins at Shannon Campground. Heliograph Peak contains a 100-foot lookout tower and has excellent views of Mt. Graham.
The Summit: Mount Graham’s summit is a mix of conifer trees and grasses. There is a small rock pike at the highest point, which contains a summit register. There is a large white square structure just below the summit housing one of the more advanced telescopes for the Mt. Graham International Observatory.
TRIP SUMMARY
Date Visited: April 25, 2026
Route Used: Dirt road and cross-country travel – 8.7 miles (round-trip)
Mount Graham is a tricky CoHP to discuss because the summit is technically closed to the public. This closure isn’t cultural (as with the Apache CoHP), or safety-related, or even due to private ownership. It has everything to do with squirrels, more specifically, the Mt. Graham Red Squirrel (MGRS).
These tiny squirrels only weigh about 8 ounces, and they have a unique tail that isn’t fringed in white like other more common squirrels in southern Arizona (e.g., Arizona gray squirrels, the tassel-eared Abert’s squirrel, Chiricahua fox squirrel, etc).
This small red squirrel subspecies was believed to be extinct in the 1950s, but it was “rediscovered” in the Pinaleño Mountains in the 1970s. As a result, the GMRS was officially listed as an endangered species in 1987 and has remained in that status for the past 40 years. To help preserve its habitat, the US Fish and Wildlife Service (USFWS) designated most of the top of this mountain as a special refuge area, accessible only by special permit.
After years of living in this protected habitat, the GMRS population took another massive hit in 2017. A summer lightning strike ignited the Frye Fire, which burned 48,842 acres on Mount Graham, and further shrank their numbers to just 35. They’ve since rebounded to roughly 230-235 squirrels in 2024, but the MGRS numbers are still remarkably low.
Interestingly, one year after the MGRS was listed as endangered, the University of Arizona was granted special permission to build the Mount Graham International Observatory near Mt. Graham’s summit (i.e., within the Red Squirrel Refugium). Part of this compromise required the university to track the MGRS population within 300 yards of the astrophysical observatory to determine whether human activity is impacting the species.
And so, I had to decide whether to: (a) hike up the 5-mile dirt road to the summit of this ultraprominent peak, or (b) choose another subpeak on the mountain instead.
Mount Graham has three other distinct subpeaks (Heliograph Peak, Webb Peak, and Clark Peak) that are open to the public for hikers who want to climb part of the CoHP without entering the Red Squirrel Refugium surrounding the mountain’s true summit. All three of these subpeaks are part of the Arizona 20-20 Challenge, which includes hikes to Arizona’s 20 highest mountains and 20 deepest canyons.
In the end, I decided to risk trespassing. I didn’t have any moral qualms about my hike negatively impacting these squirrels. I intended to hike solo and avoid any trees with dreys (twig nests that might contain baby squirrels) or middens (food caches). And it wasn’t as if the squirrels weren’t already coming into regular contact with humans, due to the USFWS’s tracking efforts and the comings and goings at the observatory.
And so, I left my hotel in Safford on Saturday morning to begin the slow, curvy drive up to Mt. Graham. The Swift Trail Parkway (AZ-366) is the only route up to Mt. Graham, and it was going to take at least an hour to drive the 21.8 miles to the start of my hike.
My starting point in Safford, near the base of Mt. Graham, was a modest 2,900 feet in elevation. But I needed to drive up to just beyond the Shannon Campground at around 9,100 feet. And so, as the road curved back and forth into the Pinaleño Mountains, I watched the roadside elevation signs come one after another. First 4,000 feet elevation, then 5,000 feet, 6,000 feet, 7,000 feet, 8,000 feet, and 9,000 feet. I was essentially climbing 1,000 feet of elevation for every 3 miles of pavement.
Not long after the signs for Shannon Campground, I reached a large turnaround point. This was where the paved road ended, and a dirt road continued toward the Columbine Visitor Center, the Mt. Graham International Observatory, and trailheads for Webb Peak and Clark Peak.
There were already two other cars parked in there, which kind of surprised me. It was a Saturday morning, so it wasn’t unfathomable that I’d run into other hikers. But given that Mt. Graham’s summit was closed, I didn’t expect to see anyone else attempting to hike up it. Was this hike more popular than I’d expected? Or did these cars belong to people who were going to try to turn me back at the refugium boundary? Only time would tell.
I grabbed my pack and some snivel gear for the hike up. It was another windy day and overcast. Plus, the warm spring temperatures in Safford didn’t extend up here on the mountain. It was a solid 25 degrees cooler up here, and only about 48 degrees according to my rental car’s thermostat!
There was a nicely groomed dirt road near the parking turnaround, and it only took a few minutes of hiking uphill it to reach the gate spanning the road’s width. None of the signs here said hiking was prohibited, and the refugium boundary was still a mile and a half further up the road. In fact, the only sign of note was a bright orange one warning about hazards ahead in the burn area.
I was sticking to the dirt road for most of this hike, so I wasn’t overly concerned about loose rocks or debris. After about 1.4 miles, I reached some USFS trail signs, but it appears as if the fire destroyed those trails, and they’ve yet to be rebuilt.
About a quarter mile later, at mile 1.7, I finally reached the refugium boundary. I still hadn’t seen any other hikers yet or the people associated with the cars parked down below. Nor was there anyone gatekeeping. There was just a simple white sign that said “Road Closed to public use. Administrative use only.”
Now was the time to decide whether to continue or turn back. If I stopped here, I could say that I’d climbed as far up Mt. Graham as was legally permissible. But I was still only at 9,800 feet elevation, and the summit was 900 vertical feet higher. This wasn’t even close.
And so, I continued up the road, telling myself that I surely had some “administrative” reason that justified my presence. Behind me, I could see the prominent fire lookout tower atop Heliograph Peak, and I decided that I would head over there once this hike was done, just to be able to see Mt. Graham from a different vantage point.
At mile 3, the dirt road curved around a bend, and I got my first glimpse of Mt. Graham’s summit and the white square box structure that held one of the observatory’s telescopes. I was now at 10,000 feet in elevation and feeling great. The road provided a nice, gentle climb for this hike.
At mile 3.4, I made the decision to leave the road and begin hiking uphill cross-country toward the saddle between Plain View Peak and Mt. Graham’s summit.
If I stayed on the road, it would eventually get me to the high point, but it would also take me past the junction where the “white box” was perched. The telescope was bound to have cameras around it, and possibly people, too. And since I was trespassing, going stealth mode and taking the most direct route seemed prudent.
My cross-country route wasn’t fast, though. The slope up to the saddle, and then onto the false summit at mile 3.9, was covered with fallen trees. The devastation from the Frye Fire was on full display as I picked my way up the hillside, trying my best not to trip over a log or large rock.
For most of the ascent, I stuck to the ridgeline, but dropped down on the east side a little to let the slope break the fierce, cold wind coming from the west. This also had a secondary benefit of shielding me from the white box and anyone who might be on the dirt road.
Just beyond mile 4.1, I made it to a small grove of pine trees near the summit. The majority of Mt. Graham’s slope was bare. But this small cluster of trees seemed to have escaped the wildfire’s fate, and simultaneously blocked whatever panoramic views I might have otherwised gotten from this 10,700-foot summit.
Inside the trees, the ground seemed to gently rise toward the high point, marked by a small pile of rocks. There was another group of rocks shaped into an arrow pointing back toward the road, as if visitors might get turned around up here and head down the wrong way (highly preposterous, in my opinion).
A jar was secreted away in the rock pile containing a summit register. I was shocked to see how many names it held, given the summit’s off-limits status. The last visitors had been there only 10 days earlier, and there were several other visitors in April, too. I guess the decision to trespass into the refugium wasn’t as big a deal as I’d made it out to be.
On my way back down to the road, I decided to crest the ridgeline, just to get a better view of the “white box” holding one of the telescopes. I’d been staring at it for so long that my curiosity got the best of me. Not that you could really see much. It was just a white square with a door on one side and a light green base that the structure appeared to rotate on.
The rest of my return hike followed my original route up. I hiked the ridgeline back down to the saddle near Plain View Peak, and then dropped down to the dirt road and followed it back to the car. All told, my route was 8.7 miles round-trip, and I hadn’t seen a soul. I had no idea where those other people had gone, but it wasn’t up to the summit of Mt. Graham.
With my 13th Arizona CoHP complete, I decided to scoot over to Shannon Campground to see about hiking up Heliograph Peak, too. The trailhead was at the far end of the campground, and it was just a short 1 mile up the Arcadia Trail (#328) to Eagle Rock, followed by 1 mile up the Heliograph Trail (#328A).
Unlike my road hike up Mt. Graham’s burn area, these two trails were nice single-track trails through the pine and aspen forests. The Heliograph Trail was slightly steeper than I’d been expecting, or maybe it just felt that way because my legs were tired.
When I reached the 10,000-foot summit, I was met with a log cabin, a 99-foot high fire lookout tower, and a few ugly microwave towers beside them.
Signs near the Heliograph lookout tower provided me with some interesting historical information. The summit got its name from its former use as a U.S. Army heliograph signal station in 1866. Soldiers used this vantage point to send signals via mirrors and Morse Code to troops below about Apache movements in Arizona and New Mexico.
In 1933, the Civilian Conservation Corps built the log cabin and the 99-foot fire lookout as part of a string of fire-prevention camps throughout the Coronado National Forest. There was even a photo of the fire lookout that once stood atop Mt. Wrightson (the Santa Cruz CoHP that I’d hike up in February 2025.)
From this vantage point, Mt. Graham’s summit seemed like gentle hills on the horizon. It was a wholly different perspective than viewing the uber-prominent mountain from down in Safford, where it towered over the Sonoran and Chihuahuan deserts.
This sky island might be the most scientifically significant of the Arizona CoHPs. Between the observatory, the red squirrel refugium, the former heliograph station, and the different ecosystems I drove through to get up here, Mt. Graham definitely left a strong impression on me.
BONUS MATERIAL
Public camping nearby:
- Shannon Campground is located on Mt. Graham near Heliograph Peak. This high-elevation USFS campground (May to October) and offers 11 campsites, vault toilets, and picnic tables. There is no potable water, and this campground is in a black bear area, so all food and trash must be stored in bear-proof containers and/or locked inside a vehicle. Campsites are available on a first-come, first-served basis. Cost: $15/night
- Roper Lake State Park is located just south of Safford, AZ. This state campground is open seasonally (May 1 to September 30) and offers 45 paved campsites (with water/electric), 5 dry camping campsites, 8 cabins, flush toilets and showers, recreation trails, a dog run, a general store, RV dump station, boat ramp, fishing, and water activities. Online reservations are available. Cost: $25/night (dry camping); $50/night (water/electric).
Resources:
- Mount Graham Overview (Summit Post)
- Mount Graham Recreation Guide (USFS)
- History of Mt. Graham (University of Arizona)
- Arizona 20-20 Challenge