The Grosvenor Hills | Desert Mountaineer

Back in 2014, climber friend Andy Martin called me and suggested we go and climb an un-named peak that happened to be the highest point in the Grosvenor Hills (the “s” in Grosvenor is silent). It seemed like a good idea, and I quickly agreed. It wasn’t too far from home, so it was a bit surprising that we hadn’t climbed it earlier. The peak was a bit mysterious in that there didn’t seem to be too much information about it – a couple of our friends had been in there a decade earlier, but other than that, it was kind of an unknown. It was in a rugged area down close to the Mexican border, but it looked like we could drive to within a few miles of it. In preparing this story, I did some research and came up with some interesting details about the area, which I’ll share with you here.

First of all, the name. The hills were named after one Horace C. Grosvenor, whose short life spanned the years 1820 to 1861. He’s remembered as an engraver and mining superintendent, and was known for his role in the early development of the Arizona Territory. Originally from Cincinnati, Ohio, his sketches and engravings appeared in notable early works such as Doniphan’s Expedition (1847). In 1858, he moved to Arizona to serve as the manager and superintendent of the Santa Rita Mining Company (later part of the Salero Mining Company) near Tubac, Arizona. He is often cited in the memoirs of geologist Raphael Pumpelly who worked under him. Grosvenor’s 1860 drawing of the Dragoon Springs Stage Station remains a critical historical record of the Butterfield overland mail route.

Grosvenor was killed by Apaches on June 25, 1861 while walking alone near the Santa Rita Mines. He was buried at the mines. His death is noted in historical records as one of the first Masonic burials in Arizona. The 1861 Apache attacks decimated the Santa Rita Mining Company, a venture that represented one of the earliest American efforts to extract silver from the Arizona Territory. The Santa Rita Mining Company was established in 1858 as an offshoot of the older Sonora Company. It operated mines east of Tubac, Arizona in the Santa Rita Mountains. Grosvenor was an early figure there who served as superintendent until his death. The headquarters, often called the Hacienda de Santa Rita, was a fortified adobe structure intended to protect miners and supplies from raiding parties.

The violence of 1861 was largely precipitated by the Bascom Affair in February, where a botched attempt by the U.S. Army to arrest Cochise triggered a decade-long war. On April 25, 1861, Pinal Apaches attacked the Santa Rita Mountains, killing three civilians associated with the operations. On June 15, 1861, Horace Grosvenor was ambushed and killed while returning to the hacienda. Shortly after Grosvenor’s death, the withdrawal of U.S. troops for the Civil War left the region without protection. The mines were abandoned as survivors fled to Tubac or Tucson to escape the “Apache Menace”. The violence continued for years; in 1865, surveyors William Wrightson and Gilbert Hopkins – the namesakes of the region’s highest peaks—were killed nearby after an attack on Fort Buchanan. The ruins of the Santa Rita Mining Company operations are now largely lost to time, though the Santa Rita Mountains and landmarks like Grosvenor Hills remain as geographic tributes to the era.

Horace C. Grosvenor’s artistic legacy and the harrowing accounts of the 1861 attacks are primarily preserved through the memoirs of those who worked alongside him. Grosvenor was a skilled wood engraver and illustrator whose work provided a rare visual record of the pre-Civil War Southwest. Some of his most famous works are as follows: “Dragoon Springs Stage Station” (1860) – his most famous historical sketch, depicting the isolated Butterfield Overland Mail station in Arizona; “Hacienda of the Santa Rita Mining Company” – a detailed drawing of the fortified company headquarters where he lived and worked; illustrations for Doniphan’s Expedition, a detailed drawing of the fortified company headquarters where he lived and worked. Before moving to Arizona, he created numerous engravings for John T. Hughes’ 1847 account of the Mexican-American War, depicting landscapes and military engagements. He documented early silver mining techniques and the rugged terrain of the Santa Rita Mountains through various field sketches. I found this photo of Grosvenor online.

Survivors’ accounts of the 1861 attacks: the primary source for the 1861 collapse of the Santa Rita Mining Company is geologist Raphael Pumpelly whose memoirs provide a vivid, firsthand look at the chaos. Pumpelly recounts finding Grosvenor’s body on June 15, 1861. He describes a scene of brutal efficiency; Grosvenor had been ambushed by a large party of Apaches just 1.5 miles from the hacienda. Following the murder, the remaining miners—including Pumpelly and Poston—were effectively trapped. Pumpelly describes nights of “terrible suspense,” hearing the signals of Apache raiders in the surrounding hills. With no military protection available due to the start of the Civil War, the survivors abandoned the silver bullion and fled toward Tubac. They described the region as a “charred wasteland,” with every ranch and mining camp they passed having been burned or abandoned.

Charles Poston, the “Father of Arizona,” also wrote extensively about this period, detailing how the sudden withdrawal of Federal troops acted as a green light for the Apaches to reclaim the territory. Here is his timeline of the 1861 Regional Collapse: February – the Bascom Affair at Apache Pass ignites full-scale war; April 25 – Pinal Apaches attack the Santa Rita Mountains, killing three company employees; June 15 – Horace Grosvenor is killed in an ambush; July – U.S. troops abandon Fort Buchanan,
leaving the Santa Cruz Valley entirely defenseless; August – the remaining Santa Rita miners flee to the coast, marking the end of early American mining in the area.

Horace Grosvenor was a member of the Masonic Order, and his internment is recognized as one of the first Masonic burials in Arizona. Despite the imminent threat of further Apache attacks, Raphael Pumpelly and other survivors performed a makeshift Masonic service. Because no formal lodge existed in the territory yet (the Grand Lodge of Arizona wasn’t formed until 1882), the service was a rare act of “civilized” ritual in a region descending into chaos. He was buried near the Santa Rita Hacienda. For decades, the site was lost to the elements, but it remains a point of interest for Masonic historians tracing the fraternity’s pioneer roots in the Southwest.

The Santa Rita Mining Company used a blend of German engineering and traditional Mexican smelting known as the Patio Process and the Adobe Furnace.

Extraction: Miners used hand drills and black powder to blast silver-lead ore from the mountainside. The ore was then hauled to the surface in leather bags called tenates.

The “German” Cupellation: Under Grosvenor and Pumpelly, the company utilized cupellation, a process where ore is heated to high temperatures in a furnace; the lead oxidizes and is absorbed, leaving behind a “button” of nearly pure silver.

The Mexican Blast Furnace: They built Adobe Furnaces (called hornos) fueled by local mesquite charcoal. These were efficient but required constant manual labor from Mexican buscones (prospectors).

Currency: Due to the lack of minted coins, the company often paid workers in boletas—printed slips of paper redeemable for goods at the company store, a common practice in isolated Arizona mining camps.

While the hills themselves are natural features, the specific locations tied to Grosvenor’s life are in various states of preservation: Santa Rita Mining Site – the original site of the Hacienda de Santa Rita is located on private or restricted land in the Santa Rita Mountains. Very few physical remnants of the 1860s adobe structures remain visible today. The exact location of the first Masonic Burial site is considered a “lost” historical location, though it is generally cited as being near the foot of the Santa Rita Mountains east of Tubac.

Okay, I’ll move on to our actual climb, the reason we went there in the first place, although I’m glad I was able to gather all of the preceding historical details for you.

In southern Arizona, along Arizona Highway 82, about half-way between Nogales and Patagonia, we found the start of Salero Road. After a couple of miles, the name changes to Forest Service Road 143. It was only 8 miles along the excellent dirt road that we drove to reach our trailhead, but en route we passed near the old Salero Mine.

This is one of the oldest mines of the district. Discovered by the pioneer Jesuits and worked about 1828 to 1830 by the Tumacacori missionaries, and later by Mexicans, it was worked by early Americans prior to 1900, and only on a small scale since then. Total production would be some 500 tons of ore averaging about 12% Pb, 24 oz. Ag/T, less than 1% Cu and zinc, and minor gold.

The map shows that all of the area around our climb is a part of what is called Luis Maria Baca Float No. 3. I went online and learned this:

The Treaty of Guadalupe Hidalgo of 1848 and the Gadsden Purchase of 1853 transferred approximately 560,000 square miles of Mexico to the United States. It took more than a half-century for the courts to unscramble myriad rival claims to the Spanish and Mexican land grants included in the Mexican Cession. The controversies in southern Arizona surrounding the Tumacacori, Calabasas and Baca Flora grants resulted in several noteworthy U.S. Supreme Court decisions. The land that comprised Baca Float Number Three lies totally within the Sonoran desert in Santa Cruz County, Arizona and the Santa Cruz River, an intermittent water source, flows through the float and has played a critical role in its history. The legal and institutional history of the Baca Float Number Three clearly demonstrated that private property rights were protected under the Treaty of Guadalupe Hidalgo and the Gadsden Purchase, and at the time of Arizona statehood in 1912, these rights could not have passed in trust from the United States Government to the State of Arizona. Significantly, in 1860 the United States Congress acknowledged the validity of the Mexican grant and this notion was affirmed in subsequent federal court cases. The historical record is clear: the United States pledged to respect property fights of Mexicans in the ceded territories and subsequent Supreme Court decisions interpreting the treaty language asserts that successors in title to lands originally belonging to Mexican landholders enjoy the full right and benefits of their Mexican predecessors.

We parked on the side of the road. Across from our parking spot, another road started south, and that was the one that we wanted to travel. A big metal gate blocked the way. We had brought bicycles with us, thinking that they might come in handy, and it appeared that they would. We wrangled the bikes over the gate and, wearing our day packs, started south down that road (it is shown on Google Maps as Calle del Ensueño). What a ride! One minute, we’d be coasting down a steep hill really fast, and the next we’d be pedaling hard uphill. Up and down, up and down. My map program says that in the next 1 1/4 miles we pedaled uphill a total of 232 vertical feet, and coasted downhill a total of 147 vertical feet. This brought us to where a lesser side road branched off to the west. We followed this road for a mile, but it soon became too rough to ride, and where it did, we ditched the bikes. There we were, at around 4,700 feet in the lower reaches of Cieneguita Canyon (it means “little swamp”), and it was from there that we had our first good view of our objective.

Our first glimpse of Peak 5466, in the distance over the ridge.

We set off cross-country and soon headed over a low saddle and dropped down into Coal Mine Canyon. The closer we got, the better it looked. Here is what we saw as we got nearer.

A nice-looking peak. That’s the northeast side.

It was an enjoyable scramble to reach the top of Peak 5466, the high point of the Grosvenor Hills. Considering the fact that it has a full thousand feet of prominence, it’s surprising that there are only 5 climbers of record who have climbed it, and the last 3 of us did it in 2014. We signed in to the register left by Mark Nichols in 2001, then sat a while and enjoyed the view. To the west, we had this unbroken view of the San Cayetano Mountains.

Looking west. The range high point, San Cayetano Peak, is in the middle, with almost 2,000 feet of prominence.

Then there was this million-dollar view to the north. Eleven air miles away, we can see three prominent peaks on the horizon. The one on the left is Mt. Hopkins, elevation 8,580 feet. If you zoom in, you can see something white on its summit. That’s the Smithsonian Astrophysical Observatory. The tallest peak, over on the right, is Mount Wrightson, elevation 9,453 feet. Further over to its right and lower is Josephine Peak, elevation 8,478 feet.

Looking north to high peaks in the Santa Rita Mountains.

Here’s where we sat on the summit and had lunch.

On top.

Here’s a view looking down, showing much of the way we’d come in.

Our route came up the light-colored valley cutting diagonally across the photo from mid-left to just above center.

It was easy-enough going to get back to our bikes, and the ride back out to the gate was straightforward, except pedaling the steeper uphill parts. Something strange happened, though, as we got back to the gate – it opened! Perhaps there was a sensor there that saw us? Who knows? If it had opened for us when we arrived on our way in, we could have driven all the way to the road’s end and avoided the bike ride. Oh well. When we got back to the truck, we put the bikes in back and drove back out to the east. We had one more stop to make, though, and after barely 3 miles of driving, we pulled over and did a quick climb of Peak 5077. Click the link to see a photo – easy peasy. The drive out and home was easy. It was nice to get a glimpse into an area with so much mining and ranching history.