Saguaro Lake History: How Stewart Mountain Dam Got Its Name

Saguaro Lake is the reservoir behind Stewart Mountain Dam, a concrete thin-arch dam on the Salt River built between 1928 and 1930. The dam took its name from the Old Stewart Ranch that once sat nearby, and the camp built for its construction crews later became the Saguaro Lake guest ranch.

I'm Terry Day, and when people who live in northeast Mesa ask me where the weekend crowd disappears to, the answer is usually Saguaro Lake. It sits about 31 miles from Mesa by way of the Bush Highway, tucked into canyon walls in the Tonto National Forest. Most folks know it as a place to launch a boat or spread out a picnic. Fewer know it started as a power and water project during the Roaring Twenties, and that the lake's name and the dam's name tell two different stories.

The Last of Three Dams on the Salt River

According to Salt River Project, Stewart Mountain Dam was the last of three dams built on the Salt River between 1923 and 1930. The other two are Mormon Flat Dam and Horse Mesa Dam. Together, SRP says, those three dams more than doubled its hydropower generating capacity and gave it much better control over the water it releases for irrigation.

There was also a money side to the story. SRP explains that the power revenue from these three dams was used to repay the federal government for building Roosevelt Dam and to pay off the bonds that financed the newer, lower dams. In other words, the electricity helped pay for the water system the Valley still leans on today.

Construction on Stewart Mountain began in 1928 and wrapped up in 1930. It is a concrete thin-arch dam, more than 200 feet tall, owned by the U.S. Bureau of Reclamation and operated by SRP. It still holds a hydroelectric unit, which runs mostly during the summer months when Valley air conditioners are working hardest.

Where the Name Stewart Mountain Came From

The dam is named for the Old Stewart Ranch, a ranch that used to sit near the site. That detail shows up in both SRP's history and the dam's National Register record. The sources I checked don't say much about the Stewart family themselves, so I'll leave that part of the story where the record leaves it.

What we do know: in 1927, a camp went up just below the dam site to house the crews. SRP notes it once served as a residence and chow hall for the workers. After the dam was finished, that camp became the Saguaro Lake guest ranch, which still welcomes overnight guests along the river below the dam.

In 2017, Stewart Mountain Dam was listed on the National Register of Historic Places as part of a group of Salt River Project historic resources. Not bad for a structure most people only see from the deck of a boat.

How a Reservoir Became a Desert Playground

The lake behind the dam covers roughly 1,260 acres, and SRP says it has more than 22 miles of shoreline. The Forest Service describes it as set in the Sonoran Desert, rimmed with canyon walls and shores studded with saguaro cactus, at about 1,500 feet in elevation. SRP manages the water and the Forest Service manages the recreation sites.

One thing that surprises newcomers: the water level moves. The Forest Service says the lake rises and falls daily based on irrigation demand and power generation, so rocks can sit just below the surface. It is still a working reservoir, nearly a century later.

Boating culture here goes back decades. The Desert Belle, a double-decker tour boat, first launched in 1964 and has been cruising Saguaro Lake for more than fifty years. Its 90-minute narrated cruise covers the history, geology and wildlife of the canyon, and it is the easiest way to see the lake if you don't own a boat.

Visiting Saguaro Lake Today

From Mesa, the Forest Service route is 27 miles north on State Route 87, then a right on the Bush Highway (Forest Road 204) for about 4 miles to the lake. A few spots worth knowing:

• Butcher Jones Day Use Area: a gently sloping beach with a buoyed swimming area, shaded picnic units and the Butcher Jones Trail, about 5 miles out and back. It is day use only, has vault toilets and no drinking water, and fills quickly in spring and summer.
• Saguaro Lake Marina: on the Bush Highway, with boat rentals, a fuel dock and a store.
• Bagley Flat: boat-access-only camping at the quieter east end of the lake.
• Stewart Dam Petroglyphs Trail: a hiking option SRP lists near the dam.

For boating, the Forest Service requires a Tonto Daily Pass and Watercraft Sticker or a Tonto Discovery Pass. On most weekends and holidays from April through October, the lake hits its boating capacity early in the day and more boats are turned away, so get there early. Glass containers are not allowed, and there is no trash service, so pack it out.

Living close helps. From neighborhoods like Red Mountain Ranch and Las Sendas, the Bush Highway is right there. If you'd like the bigger picture of the city, my Moving to Mesa guide covers it, and you can browse homes for sale in Mesa. On the drive up, you'll pass the park I wrote about in How Usery Mountain Got Its Name.

Questions People Ask

Why is it called Stewart Mountain Dam?
It is named for the Old Stewart Ranch, which once sat near the dam site on the Salt River.

When was Saguaro Lake created?
Saguaro Lake formed behind Stewart Mountain Dam, which was built between 1928 and 1930. It was the last of three Salt River dams SRP built in that era.

How far is Saguaro Lake from Mesa?
It is about 31 miles by the Forest Service route: 27 miles north on State Route 87, then about 4 miles on the Bush Highway.