Every day, tens of thousands of cars barrel down Interstate 10, a highway that hugs the western edge of Tucson, Arizona. Many of these drivers may not realize that they are driving past a region with one of the longest food heritages on the continent. Often considered the birthplace of Tucson itself, this swath of Sonoran Desert nestled at the base of the Tucson Mountains is where the O'odham people settled, planting crops of maize, tepary beans and other produce amid a landscape punctuated by prickly pear cacti and sagebrush.

This vast agricultural past, along with a thriving culinary scene that rivals those found in much larger urban areas, is what helped this city of more than half a million people earn the coveted title of Unesco Capital of Gastronomy.

Over the holidays, Unesco added 47 cities in 33 countries, including Tucson, to its growing Creative Cities Network. Tucson is the first place in the United States to be honored with the Capital of Gastronomy designation. (Other cities that earned the title for 2015 include Belém, Brazil; Bergen, Norway; Phuket, Thailand; and Tucson’s sister city, Ensenada, Mexico.) Launched in 2004, the network consists of 116 cities in the creative fields of crafts and folk art, design, film, gastronomy, literature, media arts and music. The purpose of this international network is to strengthen creative partnerships between different cities and encourage sustainable urban development worldwide.

Why Tucson? Though Unesco didn’t formally explain its reasons for including the city in its network, Jonathan Mabry, historic preservation officer for the City of Tucson, thinks he may have the answer.

“It all starts with our deep and multicultural food history,” he tells Smithsonian.com. “There’s so much innovation in all parts of our food system, including sustainable agriculture and ranching, plus the development of an innovative urban agriculture scene. For example, Tucson recently amended our land use code to make it easier to do agriculture within city limits and to sell those products.”

Mabry was responsible for writing the application that helped Tucson snag the Unesco designation (his completed application is available here). Even he was surprised at the wealth of food-related accomplishments the city has achieved over the years, from the ancient O’odham mountainside settlement to the many local organizations striving to help battle hunger, like the Community Food Bank of Southern Arizona and Iskashitaa Refugee Network. And then there’s the food itself: The city is packed with restaurateurs, chefs, farmers and ranchers who nurture a vibrant food scene.

One of those local food boosters is Janos Wilder, a James Beard Award winner and chef/owner of Downtown Kitchen + Cocktails. His bar and restaurant incorporates local ingredients like tepary beans, a drought-resistant legume native to the American Southwest, into dishes like a Cholla bud escabeche served alongside a green bean and tepary bean salad and drizzled with a jalapeño-orange vinaigrette. When Smithsonian.com talked to Wilder, he was in the early stages of writing out a quintessentially local menu for a conference he’ll attend this spring as the city’s representative.

“I’m thinking that I might pickle some Cholla buds or add some purslane into a dish, since it grows wild in Tucson’s dry riverbeds,” Wilder says. “I’ll probably make a syrup out of some Saguaro cactus blossoms.”

Wilder is preparing another venture: the Carriage House, a downtown events space that will open later this month and feature cooking classes. Fittingly, his first class will focus on cooking with local ingredients.

“Using ingredients from the desert has always been important to me,” he says. “Even when I opened my first restaurant here in 1983, I ran an ad looking for local gardeners before I ran one to hire staff.”

Residents citywide heard his call. They arrived soon thereafter with armloads of squashes, chilies, herbs and other edibles they had grown in their own backyards. Even today, Wilder has a working relationship with many area farmers and gardeners. He also taps into his own thriving garden adjacent to his restaurant and the one he nurtures at the Children’s Museum Tucson a block away.

But the city’s burgeoning food scene of restaurants, food festivals and farmers’ markets isn’t the only thing that makes it a gastronomy capital. At a more organic level are organizations like Native Seeds/SEARCH, a nonprofit seed bank that conserves and distributes heirloom seeds found across the Southwest. Many of the crops that Wilder and other chefs cook with evolved from the very seeds provided by Native Seeds/SEARCH, bringing Tucson’s agricultural history full circle.

“There’s such an unexpected biodiversity in the city’s desert borderlands,” Mabry says. “There are more heritage foods grown within 100 miles of Tucson than any other city in North America.”

Another organization, Mission Garden Project, seeks to bring focus back to the city’s extensive agrarian lineage. The project is the brainchild of the Friends of Tucson’s Birthplace, a non-profit organization that re-created the original walled gardens built by Father Eusebio Francisco Kino, a Jesuit missionary from Europe who settled in the area in the 17th century. The site is located on the same fertile ground where the O’odham people grew their crops more than 4,000 years ago. They named it Cuk Şon or “black base.” Mission Garden Project interprets different distinctive periods of Tucson’s agricultural history, from the O’odham through the Spanish, Mexican, Chinese and Territorial Anglo-American periods, re-creating them in the form of public gardens, vineyards, and orchards.

Gary Nabhan, Ph.D., director of the Center for Regional Food Studies at the University of Arizona and founder of Native Seeds/SEARCH, has been a key partner to the organization. He helped plant the seed, so to speak, that got Tucson considered for the Unesco designation.

“There's a real pride here in Tucson,” he tells Smithsonian.com, “not only of the city’s rich agricultural heritage, but of the many recipes linked to it. It’s that intangible cultural heritage that ties Tucson’s present food scene to its past.” With the help of Unesco and the city’s ongoing appetite for celebrating its culinary roots, the future is bound to be just as delicious.