A legendary Arizona river is under threat
Record heat in Phoenix adds pressure on the Salt River, a humble waterway with an ancient history.
Less than an hour outside of America’s fifth-largest city is a watery playground in a region known for a lack of water. Fed by high-altitude springs and streams a hundred miles to the northeast, the Salt River flows down from the mountains and through Phoenix, Arizona, before it joins the Gila River.
Most visitors to Phoenix aren’t aware of the Salt River’s wealth of outdoor adventures, from kayaking and tubing down the 12 miles of the Lower Salt to fishing for rainbow trout and redbreast sunfish to picnicking with family at Pebble Beach Recreation Area.
Yet even savvy, heat-escaping locals don’t know of another secret: how the humble Salt River helped create modern Phoenix.
Starting around 600 A.D., the ancestors of the contemporary O’odham peoples—Huhugam is the O’odham term for ancestors—used stone tools to dig hundreds of miles of sophisticated irrigation canals in what is now known as the Salt River Valley. By creating the largest and most complex irrigation system in ancient North America, the Huhugam transformed the valley agriculturally, making it easier to create a settled community. Yet their legacy, and even their descendants’ ongoing presence, is just now beginning to be accurately understood.
“People really don’t understand that they’re standing on the shoulders of giants,” says Angela Garcia-Lewis, cultural compliance officer with the Salt River Pima-Maricopa Indian Community. “The irrigation that we use today, the majority of the contemporary canals have been in existence for thousands of years.”
Beyond being a source of Phoenix’s water, electricity, and recreation, the managed river is also a conservation corridor, particularly for endangered birds and reptiles like the western yellow-billed cuckoo and the Chiricahua leopard frog.
(Rivers and lakes are the most degraded ecosystems in the world. Can we save them?)
“This is a unique ecological visiting opportunity,” says Jon Colby, a river guide for over 30 years and manager of REI Experiences Arizona. “It’s all for non-motorized use. So it retains a little bit more of the natural quality of what the pre-European civilization riverbed would have been.”
From Sonora tiger salamanders to the spa goers at the local resorts, all have the Salt to thank. Says Colby, “Phoenix was built on the banks of this river that flows perennially through the desert and makes life possible.”
Ancient cultural history
By 1450 A.D., the culture that archaeologists call Hohokam had created the largest expanse of irrigated land north of Peru along Arizona’s Salt and Gila rivers. Their network supplied water for an estimated 110,000 acres at its peak. Some investigated canals are 15 feet deep and up to 45 feet wide. Many are still in use by the valley’s cities.
Recent archaeological finds in Tempe and Mesa, along with holistic, conservation-based exploration, are increasing the local public’s awareness of the engineering feat that connects past to present. Irrigation means sustainable agriculture and industry, which leads to permanent settlements. Communities need dependable water to stay put, and the Salt River gives that to Phoenix. But the complex and evolving culture that laid the foundation for the valley is still misunderstood.
“Ancient farmers lived through a wide variety of dramatic and traumatic change. Droughts, floods, political and social change. People are very resourceful and persistent through that time,” says Chris Caseldine, an archaeologist at Arizona State University. “The canals connect people to that past, but the important thing is the descendants of the ancient farmers and irrigators, they’re still here.”
(This little-known Native American society was once as powerful as the Aztecs and Incas.)
The enduring myth in popular literature is that the Hohokam were a tribe of people that disappeared around 1450 A.D., perhaps from extending the canals past their capabilities and running out of water. At times they’ve been a cautionary tale for today’s resource managers. But Garcia-Lewis and others push back against this, citing a misinterpretation.
“When the Spanish missionaries asked who built those ruins we said the Huhugam, those that have died, our ancestors,” says Garcia-Lewis. “We recognize our ancestors all the way back from time immemorial living in this space. We didn’t disappear anywhere. We actually live right down the road.”
And the Salt River Pima-Maricopa Indian Community confederation, along with the rest of the Phoenix metropolis, continues to depend on the same river the Huhugam first harnessed.
A rare, forested river in the desert
The Salt has yet another surprise awaiting upriver: a forest. In a desert.
Not just any desert forest, but one that explodes with biodiversity. A lush canopy of deciduous cottonwoods and willows soars above a mix of Sonoran scrub, cacti, desert grass, and the desert’s typical trees, the scrubby, hardy mesquites.
“The contrast is what really surprises [visitors],” says Colby. “It is dramatic. Those who live here can tend to forget the shock. You’re driving through cactus and rocks and bare soil and then all of a sudden you’re at the river. You’re underneath the trees and there’s vegetation everywhere. It’s a ‘wow, how did we get here?’ moment.”
Like most desert rivers, the Salt River starts in more hydrated areas. It originates in Arizona’s highlands from the streams of the Mogollon Rim and the White Mountains northeast of Phoenix. While Phoenix gets less than 10 inches of rain a year, the high country can get over a hundred inches of snow yearly. Dams and management keep the modern river flowing over 200 miles yearlong. Yet, while the ever-ready “oasis” description certainly fits the Salt River, it minimizes the significance of its unique, and shrinking, ecosystem.
It’s hard to picture a deciduous forest in a desert. Probably because there are only 20 such stands of this Fremont Cottonwood-Goodding Willow Forest left anywhere. Before mismanaged dams and overgrazing damaged the meandering channels that make them possible, these subtropic forests flourished along the rivers of the Sonoran Desert in Mexico and the United States.
(Two-thirds of the longest rivers no longer flow freely—and it's harming us.)
So the Salt River not only maintains human life in the area, but is one of the last preserves for diverse desert wildlife. The majority of Arizona’s bald eagles nest in the Salt River corridor. The endangered southwestern yellow flycatcher and western yellow-billed cuckoo share riverside realty to snap up insects. Reintroduced Southwestern river otters flip about with a variety of fish and reptiles. A sharp eye can glimpse bighorn sheep scrambling on the cliffs above the canopy.
Most visitors hope to see the iconic feral horses. There’s a profoundly romantic pull to the idea of carefully gliding by horses drinking from the river. And since receiving legal protection from removal and harassment in 2016, the designated “Salt River wild horse herd” is officially home.
Yet, their presence is complex for many. Even terms that afford federal protection like “native” and “wild” are debated, especially after Arizona’s legislature specifically stated it was impossible to designate. The concerns about the horses’ presence include animal safety and ecological impact. Several environmental groups believe the horses pose issues with overgrazing and habitat destruction. The Salt River Wild Horse Management Group, the private volunteer partner that helps manage the herd, contends the horses have had a stable presence for centuries and that they can have positive environmental impacts.
While often passionate, the debaters have something in common. Everyone is trying to protect the symbiotic balance of the ecosystem and river that also supports a metro area of over 4.5 million people.
A vital waterway for Phoenix
As climate change, drought, and record heat raise anxiety across arid landscapes, the future of the Salt River and Phoenix are bound together.
The theory of the Hohokam expanding their canal system further than the Salt could sustain reflects our own modern fears. The Phoenix metro area has more than quadrupled its population in the last 50 years, pushing development further and further along the basin. The snow that feeds the Salt River has not quadrupled. For the Salt River to continue to supply 60 percent of the city’s water, Phoenix has attempted to “decouple water from growth” with underground reservoirs, water-use reduction, and wastewater recycling.
For Garcia-Lewis, the answer comes back to the foundational principle that her ancestors espoused and that her people still live by: Respect the connection with the landscape.
“Everything that we have today in modern society is built on the work my ancestors did in the very beginning. Nothing would exist here without that water,” says Garcia-Lewis. “People belong to the landscape, and not the other way around.”