Deer Valley Petroglyph Preserve History: 1,500 Petroglyphs in North Phoenix

The Deer Valley Petroglyph Preserve in north Phoenix protects more than 1,500 petroglyphs pecked into black basalt boulders in the Hedgpeth Hills. Archaeologists studied the site in 1980 before the Army Corps of Engineers built Adobe Dam for flood control, and Arizona State University opened it to the public in 1994.

I drive past the Hedgpeth Hills a lot when I am showing homes in north Phoenix, and most people have no idea what sits on that dark, rocky slope. It looks like any other pile of desert boulders. Get closer, though, and the rocks are covered with spirals, animals, people and shapes that were carved by hand hundreds to thousands of years ago. Here is the story of how this place was found, saved and opened to all of us.

A Flood Control Project Started It All

Skunk Creek drains a big piece of the desert north of Phoenix, and when it floods, the water heads toward the neighborhoods below. Under the Flood Control Act of 1965, the U.S. Army Corps of Engineers planned a dam to hold that water back. The spot chosen for Adobe Dam sat right against the Hedgpeth Hills.

Before building, the Corps had to know what was on the land. In 1980 it contracted archaeologist J. Simon Bruder, working with the Museum of Northern Arizona, to study the site. His crew spent about three months in the field. What they recorded was remarkable: 579 boulders carrying petroglyphs, grouped in six separate clusters across the hillside. In 1984 the site was listed on the National Register of Historic Places as the Hedgpeth Hills Petroglyph Site.

Who Made the Petroglyphs

ASU and other sources credit three ancient traditions with the rock art here. The oldest images are tied to Western Archaic people, hunters and gatherers who moved through the desert thousands of years ago. Later came the Hohokam, the farmers who built canals across the Salt River Valley, and the Patayan. Exact date ranges vary from one source to another, and ASU itself calls the 5,000-year figure a ballpark, but the oldest marks here are thought to be several thousand years old.

The makers chipped, ground or pecked through the dark coating on the basalt, called desert varnish, to expose the lighter rock underneath. Researchers have sorted the designs into 37 major types with 143 variations. The largest single image is about three feet tall. ASU staff are careful to say that the meaning of these images is not for archaeologists to decide. The Salt River Pima-Maricopa Indian Community and the Gila River Indian Community are named as descendant communities, and the preserve works with Native communities on how the site is shared.

From Rock Art Center to Petroglyph Preserve

Once the research was done and Adobe Dam was built, a museum went up on the site in 1994. Architect Will Bruder designed the building, shaped a bit like a boomerang, with landscape architect Christy Ten Eyck. It first opened as the Deer Valley Rock Art Center and later took the name Deer Valley Petroglyph Preserve.

Something people are surprised to learn: the land, the dam and the building are owned by the Flood Control District of Maricopa County, and the preserve is run by Arizona State University. It is not a city, county or state park. The preserve covers 47 acres, and it celebrated its 30th anniversary in 2024.

What a Visit Is Like Today

The preserve is at 3711 W. Deer Valley Road in Phoenix. According to ASU's current visitor pages, it is open Wednesday through Saturday from 8 a.m. to 2 p.m., with last entry at 1:30 p.m., and closed Sunday through Tuesday. Check the ASU site before you go, since hours have changed over the years.

• The trail: a quarter-mile, mostly flat gravel path with interpretive signs and a free audio tour. ASU suggests allowing about 90 minutes for the museum and trail together.
• The museum: the permanent exhibit "Leaving Marks: The Rock Art and Archaeology of Deer Valley," plus a museum store and a water refill station.
• Good to know: shade is limited, so morning is best. Only service animals are allowed on site. If you want to bring the dog, Thunderbird Conservation Park, right next door in the Hedgpeth Hills, allows dogs.

This time of year is the sweet spot. The mornings are cool, the light hits the boulders at a nice angle, and you can easily pair a visit with a walk in Thunderbird Park or a stop at Adobe Dam Regional Park nearby.

Why I Love Sharing This One

When buyers ask me about living in Deer Valley, they usually want to know about the airport, the freeways and the newer subdivisions toward Norterra and Stetson Valley. I like to mention that their new neighborhood also sits next to a preserve with more than 1,500 ancient petroglyphs. It is a good reminder that people have been calling this valley home for a very long time. If you liked this story, you might also enjoy how the White Tank Mountains got their name, another spot with ancient petroglyphs on the other side of the Valley.

Questions People Ask

How old are the Deer Valley petroglyphs?
The oldest are believed to be several thousand years old, with others made by the Hohokam and Patayan in later centuries. ASU describes the 5,000-year figure as a rough estimate, and published date ranges vary by source.

How many petroglyphs are at the Deer Valley Petroglyph Preserve?
There are more than 1,500 petroglyphs on 579 basalt boulders. ASU and other sources count about 1,571 individual images.

Can you bring a dog to the Deer Valley Petroglyph Preserve?
No, only service animals are allowed under ASU policy. Thunderbird Conservation Park, also in the Hedgpeth Hills, allows dogs.

Terry Day, REALTOR®, DeLex Realty, 10115 E Bell Rd, Scottsdale, AZ 85260.