Gu Achi Peak • Highpoint: Santa Rosa Mountains
• Tohono O'odham Indian Reservation
• Pima County

Gu Achi Peak as viewed from many miles to the north, as we were driving in

Same view, zoomed

The peak again. We went in this gate, but then backed out after discovering the road was in abysmal shape

Gu Achi Peak as viewed from below, where we started our hike

The ridge ahead, and the mine tailings of the single shaft mine that's up here

View of the summit ridge from the mine area

Approaching the serrated ridge

View of the peak as seen from the ridge

The two bumps that herald the summit, which is just a few dozen more feet behind

Me on the summit

South view, with Baboquivari Peak visible to the left

Scott descending off the summit

Scott again, as we descend the lower slopes

View of the peak from the reservation boundary fence

Montage: views along the sandy road, some rock pinnacles on the ridge, and another ridge shot showing all the cactus

Click here for Scott Peavy's images of this hike.

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Prominence Peaks


Date: February 8, 2015 • Elevation: 4,556 feet • Prominence: 2,636 feet • Distance: 4.4 miles • Time: 4 hours • Gain: 2,150 feet • Conditions: Clear and warm • Teammates: Scott Casterlin (drove), Scott Peavy

Gu Achi Peak is a peak on the Tohono O'odham Indian Reservation in southern Arizona. Its name translates as "Big Ridge" from the O'odham langauge. From a distance, it appears as a long ridge, then the big hump of the peak itself. Collectively, the peak and its subsidiary hills are called the Santa Rosa Mountains. For most people, viewing it from a distance is the only plausible option since the roads that lead close to the peak are usually minimally-maintained sand tracks that require a stout vehicle and a lot of patience. The irony is that the actual climb is quick and logical. But getting there is 90% of the battle.

Scott Peavy and I are both very close to completing the list of summits in Arizona with at least 2,000 feet of prominence. There are 73 peaks on this list, and going into today, I had 68 finished, Scott Peavy 69. In fact, I had not climbed any since November 2013, when we (along with Scott Kelley) climbed Baboquivari Peak. At the time, I felt I was "done" with this list since the remaining five peaks either had bad access or other negative factors. But I also felt that if an opportunity should arise, I would be foolish not to take advantage of it.

Scott Casterlin had offered to drive us to the peak, and we had set up our first attempt for a couple months back, but we had to make a last-minute replacement with San Cayetano Peak when rains had passed through the state, rendering the roads to Gu Achi Peak too muddy to drive. So we set up another date for last weekend, but then it rained again. So we tried for this weekend. The weather cooperated, staying dry and even getting warm for this time of year. We hoped the week of dry, warm weather would dry out the access roads.

On a map, Gu Achi Peak sits in the middle of nowhere. Even detailed atlases that show "most" roads show very few decent roads anywhere near the peak. The closest towns are Santa Rosa and Sil Nakya, both which are villages on the Tohono O'odham Nation (the TON). From there, the maps show 4-wheel drive tracks that kind-of sort-of get close to the peak. The problem is that the TON usually do not want visitors passing through their towns in the first place. The TON website is silent on how to actually get a permit, although they do give them out for certain parts of the TON. There's also the issue of the Border Patrol and the border crossers, although in this case, we were about 50 miles north of the border here. Still, it was possible we might come across a crosser or six. We would see evidence of them (discarded clothing, for example), but no actual people.

We chose to come in from the northeast, following a track that is shown on the topographical maps. This track starts at the extreme southwest corner of a grid of section-line roads south of Casa Grande and Eloy, south and west of Interstate-10. It would be a shorter drive and sidestep the need to pass through any of the TON villages. Scott Peavy had scouted these roads a few weeks ago. However, these roads are mostly soft sand and the area is very remote, so that getting stuck could be a big problem. But it was also the best of a very limited set of options.

Scott Peavy and I met Casterlin at the Love's Truck Stop on Sunland Gin Road along Interstate-10 at 6:30 a.m. We transferred our stuff into his Toyota FJ, and then started the drive, going south on Sunland Gin Road through Arizona City, a total of almost 16 miles, until Sunland Gin ended at Aries Road. We went west on Aries Road to Sagittarius Road, then south on that to the Pinal-Pima County line. So far, we were doing well, and the roads had been paved or were maintained dirt hardpack.

At the county line, we started our long, slow journey along a series of section-line roads. We knew to avoid one route along Night Sky Road because it led to a farm that was posted against trespassing, even though it looked good on the maps. Instead, we went west and south, passing through one big mud patch early on. It gets a little hard to describe exactly what we did. Generally, we stayed on this road-grid until we were as far west as we could be, now going south along a road that parallels a fence, the TON being on the other side of this fence. For a couple miles, we made very slow progress. We had to get out and walk the road to inspect it. Some parts were eroded, had bad leans, high centers, soft sand, deep ruts, or possible mud. We were concerned we may not get to the peak at this rate. Fortunately, the road conditions improved ever so slightly, from horrible to merely bad, and we were able to rumble to the first of two possible entry points onto the TON.

This entry point was gated (see third photo on the left), and we passed through the gate, but immediately realized the road was in too bad a shape to drive, so we exited, and drove east and south another three or four miles to the second of two entrance points. This one is not gated. There are no signs anywhere out here, so without a detailed map, you'd never know where you were or who owned what pieces of land.

Finally on the main track leading to Gu Achi Peak, we covered another five or six miles until we were in the heart of the range, passing through a very impressive forest of saguaro cactus along the way. This road was actually not too bad. It was mostly hard-pack, but it seemed to pass through an arroyo every few hundred feet, some with deep-cut banks. Scott Casterlin was able to get his FJ up on an elevated slope, elevation 2,400 feet, at the junction of two lonely rocky tracks. We had been driving nearly two and a half hours when we finally parked!

Peavy and I got our packs on and were ready to go in moments. Scott Casterlin would stay behind, intending to explore the other roads and tracks in the area. We were parked southeast of the summit, and somewhat of concern, it was getting very warm, possibly into the uncomfortable range. Nevertheless, we didn't delay, and were walking at 9:45 a.m., walking up an old miner's road that leads into a canyon toward a mine, about one mile in and about 900 feet of gain. The road itself was rocky and eroded, with mature brush growing in the middle suggesting that no cars have been up this road in many years.

We made good time up this road, arriving to the mine after about 30 minutes. We "spooked" two javelina. At first, I don't think they were aware of our presence. We walked a few steps and made noise, then they ran off. We then arrived to the mine and inspected it, a single mine shaft and a small mound of tailings. The road itself bent away from our intended direction, so we started the cross-country part of the hike. We crossed a drainage and onto the slopes opposite the mine.

Looking up, the peak was to the west, and a ridge to the north. We started walking upslope through open terrain, the brush being reasonably light. We could wend our way through the brush without too much trouble. In about 20 minutes, we had gained another 400 feet to put us on top the ridge, which features a series of bumps giving it a serrated appearance. We then walked west, up and down these bumps, often sidehilling when convenient. Up ahead was the only crux section of the hike, where the ridge came to a deep-cut notch. We figured we'd stay low and sidehill across the rocky slopes directly below the rock walls, and this worked well, if sloppy. Shortly, we were at this notch, elevation about 3,700 feet.

From here, the climbing was steep but easy. We had about 700 vertical feet remaining, and we went upslope, following whatever openings we could. This stretch also went well, and we were on top after just two hours. Being 2,000 feet higher, we had slightly cooler temperatures and a soft breeze. The views were tremendous in all directions, as the day was very clear. We could see peaks 80 miles away. We spent about twenty minutes up top, some of it looking for the benchmark "Santa Rosa 2", which apparently has been removed.

We retraced our route going down with no difficulties, and were back to Casterlin's FJ after 90 minutes, meaning we were gone for just under four hours. We enjoyed the hike, but didn't want to delay any more than we had to. Scott Casterlin had hiked this peak years ago and recalled it being "efficient", which was a good description. We were never slowed too severely at any time by the terrain, the brush was never too bad, it was never to steep or cliffy. We made good time the entire hike. After the brutal drive in, the hike had gone very well.

We exited by following the same track we took, which put us back to the southwest corner of the section-line roads. But rather than retrace our route out exactly, we gambled and tried a slightly different route, going east another mile or so, then north. This should have put us close to the Night Sky Road alignment, the road that went to the farm that was posted against trespassing, the whole reason we had to take that other route coming in.

We found a sand track that went north but it meandered a lot, in and out of a major wash with sections of sand and ruts. It was slow and tedious, marginally better than the road we took coming in. Finally, we came to this farm on its south end, and a gate posted against trespassing. But the gate was a simple wire-stick gate and not locked. We decided to enter anyway, and hoped that the gate at the north end was open and no one would stop us. A mile later, we discovered yes, the gate was open and that no one had truied to intercept us. Now on Night Sky Road, we had better roads, except for the large mud pit, until we got back onto pavement at the south end of Sagittarius Road. From there, we drove back to the interstate and had a lunch at a truck stop cafe.

Scott Casterlin had accrued quite a bit of mud on his FJ, so we paid for his gas and cleaned up his windshield for him. More importantly, we sincerely appreciate his willingness to drive us on those miserable roads to help us inch toward our own goals on this project. It was a successful day all around and a chance to climb this hard-to-reach peak. My thanks to the other Scotts!

Note: If you are reading this with ideas on hiking this peak for yourself, please be aware of the following:

• We were on the Tohono O'odham Nation without formal permission, which as explained above, is hard to come by, or even where to get it. We made every effort to be conscientous visitors, leaving no trace and even picking up some random garbage to clean the place up a little bit.

• The roads in from Arizona City, as described above, are really bad. If it is raining, has recently rained, or probably will rain, don't drive these roads. It's sandy, the kind that gets hopelessly mushy when wet. The desert plain out here is called the Aguirre Valley, and is a very flat plain where water does not drain fast. There are innumerable little draws intersecting the main washes. The roads are often sunk a few feet so that escaping them or turning around can be very difficult. You'll want to be here when it's been dry for awhile, and have a very capable vehicle with clearance and a strong engine.

• I deliberately was vague on the exact roads we followed, but you could probably figure it out using the topographical maps and satellite imagery. Even then, it can be hard to see details.

• If you come up from the south, you run the risk of attracting unwanted attention to yourself. Some friends who hiked here had their vehicle broken into. In fact, they knew to expect this, they left it unlocked and some old equipment they could sacrifice, and sure enough, these items were gone when they returned, but the vehicle was still there.

• Just be ready for a long drive on bad roads, and be patient. There's a reason so few people come to this forgotten part of the state.

(c) 2015 Scott Surgent. For entertainment purposes only. This report is not meant to replace maps, compass, gps and other common sense hiking/navigation items. Neither I nor the webhost can be held responsible for unfortunate situations that may arise based on these trip reports. Conditions (physical and legal) change over time! Some of these hikes are major mountaineering or backpacking endeavors that require skill, proper gear, proper fitness and general experience.