The Wa:ato: How the O'odham Made Shade in the Sonoran Desert

In the Sonoran Desert, where summer days top 110°F, shade can mean survival. People have lived here since at least 5,500 B.C.E., and long before air conditioning, Indigenous peoples such as the Akimel O'odham and Tohono O'odham built their own: open-sided, four-legged, roofed shelters called wa:ato (WAH-a-to). At the Park Service's Desert Research Learning Center in Tucson, staff built one too.

The ramada at the Desert Research Learning Center peeking over a wall, with a second ramada (under construction) visible in the distance. NPS/E. Schnaubelt.

The first ramada at the Desert Research Learning Center. Credit: E. Schnaubelt, National Park Service.

Built from the desert

The desert provided the long, strong pieces a wa:ato needs:

Photos: NPS/E. Schnaubelt.

Photos: NPS/E. Schnaubelt.

Ocotillo's woody stems made wa:ato roofs. Credit: E. Schnaubelt, National Park Service.

Shade for living and working

A wa:ato usually lasted about a season, though some were kept up as semi-permanent structures. They shaded markets and social gatherings, and extended homes — ki in O'odham — outdoors: windowless pit houses and puddled-adobe houses were very hot in summer, so much of household life moved under the wa:ato in the warm months. They also sheltered people traveling and gathering food; during the saguaro harvest, the Tohono O'odham built wa:ato to work, rest and sleep under, saving trips and letting them pick the fruit at its ripest.

The tradition continues in two national parks:

• Saguaro National Park. Since the park's Tucson Mountain District was created, the Tohono O'odham have continued their annual saguaro harvest there, and with the park they built an enormous wa:ato where family members gather each June for harvest and ceremony.
• Tumacácori National Historical Park. Each December, staff and volunteers build wa:ato to house about 50 food and craft booths at the park's fiesta, celebrating the Indigenous and historic cultures of the Santa Cruz Valley.

The learning center's ramada

The center's ramada is close to a wa:ato in size, look and its ocotillo roof, with some changes to make it taller, longer-lasting and easier to maintain:

The ramada at the DRLC stands amongst desert foliage and has a view of the stream habitat. NPS/E. Schnaubelt.

• Tamarisk legs. It stands on thicker tamarisk trunks rather than mesquite legs, since mesquite strong enough to hold the roof was hard to find. Tamarisk is an invasive non-native species — this wood came from the U.S. Fish and Wildlife Service's clearing of it at Buenos Aires National Wildlife Refuge in Arivaca, Arizona.
• Metal and concrete. The legs are reinforced with rebar and set in a cement foundation instead of staked into the ground. The O'odham did eventually obtain metal through trade from the south, but it was soft, scarce and valued for ornaments and jewelry, not building.

A second, much larger ramada was under construction, with an ocotillo roof and a frame of mesquite and material salvaged from cleared invasive plants, to shade a space for an agave restoration project and outdoor education.

The center's ramada at night. Credit: E. Schnaubelt, National Park Service.

Why build this way

Archeologists call it vernacular architecture: meeting a society's environmental needs with local materials. For the O'odham, the pressing need was shade rather than waterproofing or warmth. Using tamarisk and metal to meet the center's own needs for strength was, its builders argue, in the same spirit. Designing with the environment means less energy spent making it livable — in Arizona, less air conditioning, lower bills and less carbon dioxide — and local materials cut the emissions of transporting them. It can also deepen a sense of place and connection. People with centuries of experience adapting to a landscape, too often marginalized, have crucial lessons to offer as the climate changes.

Sources

Based on "Ramadas of the Southwest," prepared by Elizabeth Schnaubelt, Scientists-in-Parks intern, and Sharlot Hart, archeologist, National Park Service Sonoran Desert Network; a work of the United States government in the public domain. Pictures an earlier version of this page left out were restored on 2026-09-26.