Volcanic activity and millennia of erosion from wind and water shaped east-central Arizona over the course of millions of years. Through this region runs one of southern Arizona’s most scenic stretches of highway – Arizona State Highway 77 between Globe and Tucson.
Over the course of geologic history, natural forces have also made the area one of the richest in valuable minerals – including, of course, king copper. Mining these resources has further reshaped the landscape in the past two centuries.
Not only is the region rich in minerals, but it is rich in Arizona history. Small desert communities such as Oracle, San Manuel, Mammoth, Winkelman and Hayden offer a glimpse into the past – as well as recreational opportunities for visitors and Arizonans who love the natural beauty of the Sonoran Desert.
What to See
To the northeast of Tucson, past Catalina and Oracle Junction, Biosphere 2 still stands as a monument to Earth sciences and a seemingly innocent time when society had a more expansive view of the universe and our place in it.
Built between 1988 and 1991, Biosphere 2 was originally intended as an experimental self-sustaining community. It was hoped that the lessons of the experiment would assist in outer space exploration and the possible colonization of other planets.
The University of Arizona purchased the 312-acre science lab in 2011 and opened it to the public. You can visit from 9 a.m. to 4 p.m. every day of the year except Christmas and Thanksgiving. Go to biosphere2.org for details about ticket prices and tours.
Oracle, a short distance from Biosphere 2, combines the elements of a hip art enclave and outdoors Arizona in a fairly remote region – what Tucsonans call the “backside” of Mount Lemmon, at the northeastern foot of the Santa Catalina Mountains.
With several good restaurants, Oracle is a great place for a day trip. Start with breakfast at the Oracle Patio Cafe, which features homemade pies. Indoor dining is still on hold due to the pandemic, but there’s plenty of room on the patio. For dinner, try the Ore House Hilltop Tavern, surrounded by mining remnants and sculptures, offering good bar food and 16 beers on tap.
For the recreationally minded, Oracle is an Arizona Trail Gateway Community, and Oracle State Park offers miles of trails in an out-of-the-way and low-traffic area.
History buffs will want to visit the historic Kannally House, part of the state park, affording a glimpse back at the lives of early ranchers in the region. The house was built between 1929 and 1932 and stood at the heart of what was at one time a 50,000-acre cattle ranch, established in 1903.
An even older frontier home – turned B&B – is the Triangle L Ranch, part of the “Boot Ranch” established in the 1880s by rancher Charlie Moss. The house, built in 1903, is now an “art ranch” featuring ongoing art exhibits and more.
Beginning on Wednesday, April 20, Oracle Farmers Market will take place at Sue & Jerry’s Trading Post and takes place each Wednesday through October from 5-8 p.m.
The Trading Post has been in operation for 38 years and features a lavender farm as well as “Oracle’s most unique shopping experience. For details, go to Trading Post.
For the adventurous, try out the ziplines at Arizona Zipline Adventures, off-road vehicle rentals with Titan Power Rentals, and even caving at Peppersauce Caves, a series of wild underground caverns that have not been developed. Spelunk at your own risk.
As an International Dark Sky Park, Oracle State Park is a great place to be at night. Stargazing is at a premium, and the Milky Way is on display most nights.
For a taste of Oracle’s night sky, consider attending the Earth Day event on April 23 to celebrate the seven-year anniversary of the park obtaining its dark sky designation. The all-day celebration will feature hikes, workshops, tours and, of course, stargazing after dark.
East of Oracle is San Manuel, a living museum of the boom-and-bust cycles of the copper industry. The Magma Copper Company built the town when it began mining copper in the early 1950s, and before long Magma was the largest copper mine in North America.
The company town has the distinction of being the first Del E. Webb planned community. Webb was at one-time co-owner of the New York Yankees baseball club, but his true claim to fame was as a visionary post-war developer in Arizona.
San Manuel thrived for decades through several ownership changes at the mine, but that all came crashing down in 2002 when BHP Billiton abruptly halted operations and shut the mine down. On one horrific day, BHP laid off somewhere between 2,500 and 3,000 people, devastating the town’s economy in one fell swoop.
“It was horrible,” says Kathy Phipps, a 50-year San Manuel resident who volunteers at the San Manuel Historical Society Museum. “The only thing that got us through it was the way we all came together as a community and helped our neighbors.”
On Jan. 18, 2007, BHP demolished two 500-foot-tall smokestacks that had towered over the community for decades, marking a profound metaphoric end to the age of copper in San Manuel. Still, when BHP departed, turning off the pumps and leaving the mine to fill with water, it left a large copper deposit behind.
Nowadays, visitors can take advantage of the remote desert of the area around San Manuel. Off-road vehicle rentals are available through Peppersauce Motorsports. San Manuel is home to the annual San Manuel Copper Classic off-road motorcycle race, which brings people from all over the country.
The museum in San Manuel is open Wednesdays and Thursdays, but the friendly volunteers live nearby and will do their best to accommodate visitors who call contact numbers posted on the door.
A few miles to the north you’ll pass through another boom/bust town, Mammoth. Although now only a shell of what it once was, Mammoth still has a reputation for great food, found at venues such as the Rancheros Carniceria Mexican market, Mi Pueblito Tortilla Factory and Bakery, and Las Michoacanas restaurant.
From Mammoth north, Highway 77 winds its way between the Tortilla, Dripping Springs, Mescal and Pinal mountain ranges, through stands of majestic saguaros and landscapes where myriad desert fauna can be glimpsed.
Off the highway just south of Apache Sky Casino, E. Aravaipa Road parallels Aravaipa Creek for 12 miles to Aravaipa West Trailhead. This road is best traveled with a high-clearance vehicle, and recreational users must have permits.
Highway 77 is fairly flat from Mammoth to Winkelman, which sits at the confluence of the San Pedro and Gila rivers before it rolls up to the Pinals through ancient rock formations – the remnants of an ancient inland ocean, overlaid with rocks and lava spewed from the earth during eons of volcanic upheaval. There are several access points to the Gila River along the way.
Winkelman is a handy stopping point before the final leg of the journey through the mountains.
Highway 77 Throughout History
According to the book Roadside Geology of Arizona, published in 1983, this mountainous region is a remnant of a time when a great inland ocean covered the area more than 2 million years ago. When the ocean receded, it left behind sedimentation including the great limestone deposits that can be seen on the east side of the Gila River just past Winkelman.
According to the book, these mountains contain “complex arrays of Precambrian granite, schist, and quartzite, finely sliced Paleozoic limestone and quartzite, and several Tertiary granitic intrusions, shallow, rapidly cooled masses of porphyry” – the latter of which created the copper deposits that attracted so much attention from humans.
The Pleistocene Epoch was replaced by an age of volcanic activity when layers of lava and molten rock dropped over the ancient seabed. Empty magma chambers led to the collapse of the Earth’s crust, which can be seen in the patterns of the limestone ridges surrounding the Gila River.
“That’s the heart of the porphyry copper country,” says Globe geologist John Trimble. “There’s Escabrosa limestone that goes through there, and Dripping Springs quartzite. It’s got cool fossils in it: horn corals, arachnipods. It feels like we’re on an oceanfront.”
The ancient formations and remnants of creatures that died millennia ago serve as reminders of the blip humans are on the geologic timeline, Trimble says.
“It’s designed to make us humble,” he says. “We have not lasted anywhere near as long as the dinosaurs.”
More recently in time, the state of Arizona created the road we now know as State Highway 77.
According to a history of the Arizona State Highway Department published in 1939, the change from primitive roads and prehistoric trails began in the wake of the Treaty of Guadalupe after 1848, with Arizona’s territorial designation on Feb. 24, 1863. Territorial leaders realized the nascent state’s lack of roads posed a major problem, and improving them was seen as “necessary for the advancement of the Territory.”
Once Arizona became a state in 1912, the office of the State Engineer was created, which became the State Highway Department in 1927. The existing 82.8-mile stretch of State Highway 77 – from the current intersection of U.S. 70 (Ash Street in Globe) to Oracle Junction – was established in June 1938. The northern stretch of 77 from Globe to Holbrook had already been built in 1930.
By the end of 1938, Arizona had built or proposed 3,632.7 miles of highway. Much of the physical work was done by prison or day labor.
Journalist, writer and editor who has worked for community newspapers for more than 15 years. After four years at Davis-Monthan AFB and a few years living in Tucson, moved to California to find his fortune. He is happy to be back in Arizona, in the mountains he loves.