DENVER—In 2010, the restaurateur Matt Chandra told The Atlantic that the Native American restaurant he and business partner Ben Jacobs had just opened would have 13 locations “in the near future.” But six years later, just one other outpost of their fast-casual restaurant, Tocabe, is up and running.

In the last decade, at least a handful of articles predicted that Native American food would soon see wider reach and recognition. “From the acclaimed Kai restaurant in Phoenix to Fernando and Marlene Divina's James Beard Award-winning cookbook, Foods of the Americas, to the White Earth Land Recovery Project, which sells traditional foods like wild rice and hominy, this long-overlooked cuisine is slowly gaining traction in the broader culinary landscape,” wrote Katie Robbins in her Atlantic piece. “[T]he indigenous food movement is rapidly gaining momentum in the restaurant world,” proclaimed Mic in the fall of 2014. This optimism sounds reasonable enough: The shift in the restaurant world toward more locally sourced ingredients and foraging dovetails nicely with the hallmarks of Native cuisine, which is often focused on using local crops or herds. Yet while there are a few Native American restaurants in the U.S. (there’s no exact count), the predicted rise hasn’t really happened, at least not to the point where most Americans are familiar with Native American foods or restaurants.

So why are these restaurants struggling to take off when it seems like they have so much in their favor? Jacobs—who for his part says that Chandra was tossing out a random number back in 2010, and that “13” has now become something of a running joke among Tocabe regulars—offered a few potential answers from the patio of the restaurant’s first location, several miles northwest of downtown Denver. For one thing, he said, most people aren’t actually sure what Native American food is. While trying something new might appeal to adventurous eaters, it can be hard to demonstrate that there’s enough customer interest to convince those who would be financially tethered to the business. Risk-averse landlords, for instance, aren’t confident there’s enough clientele to sustain a business. That has made securing restaurant space a challenge for would-be purveyors of Native American food. “We got forced out of a lot of spots and it’s because we’re not just another pizza joint,” Jacobs, who is a member of the Osage tribe, said.

The confusion about what constitutes Native American cuisine isn’t surprising; there’s no easy definition. Of the more than 500 recognized tribes in the U.S., each has different cooking traditions shaped by access to different resources. That can make the task of launching and marketing a Native American restaurant difficult. Where one customer might expect to see buffalo and venison on a menu, another might anticipate salmon and squash. No restaurant can cater to everyone’s interpretation of what constitutes Native American food. Mitsitam, the highly regarded cafe in the Smithsonian’s National Museum of the American Indian, got around this by setting up a series of stations, each dedicated to the cuisine from a different region. “A lot of people don't really identify with native foods because they're not educated about it,” said Jerome Grant, the executive chef at Mitsitam. “We kind of educate people of the indigenous ingredients of the areas.”