Editor's note: This tour of small businesses across the country highlights the imagination, diversity, and resilience of American enterprise.

When Karlene Hunter and Mark Tilsen debuted Tanka Bars at the 2007 Black Hills Powwow, they anticipated a quiet launch. How could a single food vendor stand out among the hundreds of swirling dancers, the drum groups, the singing contests, and the general hoopla playing out around the Rushmore Plaza Civic Center in Rapid City, South Dakota?

Hunter, a member of the Oglala Lakota Tribe, recalls approaching the tribal elders--who were seated in their own section--with a basket of her startup's buffalo-meat-and-cranberry snacks. "I held my breath, because you need the elders' nod of approval or it's not going anywhere," says Hunter, the CEO of Native American Natural Foods. "They said, 'Could you send some more of that up here?' I was like, 'Thank you. Thank you.'"

Local reporters covered the event, and Hunter and Tilsen appeared on the cover of The Rapid City Journal, their cheeks emblazoned with the temporary tattoos Powwow attendees wore to get Tanka Bar samples. Soon after, the product was featured in the food section of The New York Times. "We even made Pravda," says Tilsen, the company's president.

Behind the glamour of global publicity, however, lay a 150-year-old saga of poverty and exploitation. There are many great social entrepreneurship stories out there. But few address so many ills so directly as does Native American Natural Foods.

The company, with $4 million in annual sales, is based in Pine Ridge, an Oglala Lakota reservation that inhabits a sparsely populated, starkly beautiful section of southwest South Dakota. Hunter and Tilsen come from economic development backgrounds, so the sorry statistics spill out of them. Unemployment rate: 70 percent. Average annual income: $5,600. Life expectancy: 55 years.

"These people are descendants of Red Cloud and Crazy Horse, who resisted U.S. Western expansion longer than any other," says Tilsen. "We have this beautiful place, beautiful people, a beautiful culture. And we have had no functional economy since the buffalo were destroyed."

Tilsen is referring to the government-sanctioned slaughter of American bison, which before the Civil War provided Native Americans with virtually everything they needed to survive, including food, shelter, clothing, tools, and medicine. In 1840, as many as 60 million buffalo roamed the American West. By the turn of the century, that number had dwindled to 500. (It has risen significantly since that period, especially as buffalo have been interbred with cattle.) The species's decimation was part of U.S. policy aimed at confining Native Americans to reservations.

The buffalo sustained the Lakota people in the past. With Native American Natural Foods, Hunter and Tilsen are betting the buffalo can help sustain them again in the future.

A sacred animal becomes a brand.

The idea for Tanka Bars emerged in 2005. Hunter and Tilsen, longtime business partners who met on a fundraising project for a local college, were running Lakota Express, a small Pine Ridge marketing firm that worked with nonprofits. One day, at a meeting of the local chamber of commerce, a few of the buffalo producers left on the reservation asked for ideas to increase their sales. Hunter and Tilsen suggested they create a branded food product: something healthy that promoted the positive aspects of reservation life and might scale enough to create good jobs.

"We developed this whole plan and gave it to them," says Hunter. "But these are cowboys. They said, 'We just want to sell our animals.' We looked at each other and said, 'Are you up for another launch?'"

Intent on popularizing a traditional food, the pair quickly focused on "wasna": dried buffalo meat pounded together with a high-acid fruit like cranberries or chokeberries. A hundred fifty years ago, Lakotas would wrap the meat in organ fat and store it back in the buffalo's stomach before use. Today's Native American diet is calorie-rich and protein poor, so Hunter and Tilsen skipped that step. A college professor introduced them to a fifth-generation German meat smoker who showed them how to make wasna in a USDA-compliant smokehouse.

For the next year, Hunter and Tilsen transformed Pine Ridge into a focus group. They interviewed more than 600 tribal members--elders, medicine people, kids--about everything from the recipe to the mission to whether it was OK to create a brand around a sacred animal. A focus group of teenagers named the product. "Mark and I were calling it 'Red Power Bar.' They said, 'That's so '70s,'" Hunter recalls. "They came up with 'tanka,' which is the Lakota word for 'the greatest thing you can think of.'"

The sporting and socially conscious eat it up.

At the time of the Black Hills Powwow, the entrepreneurs were still months away from full production. The unexpected publicity unleashed a flood of demand; they urged eager consumers to wait, but many insisted on placing orders. The business was online-only at first. Then in 2009 Hunter and Tilsen attended their first Expo West, a trade show for natural products. "Back then we didn't even know what a broker did," says Hunter. "We started learning about the channel."

Today, the 1-ounce, 70-calorie Tanka bars and other products, like meat sticks and jerky, are available on reservations serving more than 375 tribes. (On average, the bars retail for $2.89. Discount pricing is available for reservation sales.) They are also sold at numerous retailers, including Vitamin Cottage, REI, and Whole Foods. Sales surged when Backpacker magazine and Golf Digest championed the bars.

Whole Foods's customers like Tanka products because "they know they are not only supporting a Native-owned business but that there's a direct economic impact on the community and they're helping bring back small buffalo ranchers," says Matthew Jimenez, global grocery buyer for Whole Foods. "The fact that this is a very simple, traditional recipe also resonates with them."

The downside of the company's success has been a piling on of competitors, some professing tribal origins they don't truly possess, according to Hunter. "You look at this and say, 'Oh, it's shaman-blessed, so it must be native,'" she says, referring to a claim on the packaging of one rival product. "Well, it isn't. Something like this takes away from our people, who are the poorest of the poor."

Bringing back the buffalo and the jobs.

For Hunter and Tilsen, "our people" is what the company is all about. Having Whole Foods and REI in your corner is great, of course. But the founders care chiefly about bringing health and wealth to Pine Ridge and other reservations around the country.

Today Native producers are able to supply just 17 percent of the company's buffalo meat; Hunter and Tilsen want that raised to 100 percent. Toward that end they have partnered with a nonprofit to create the Tanka Fund, a charitable organization to restore and support buffalo farmers on Native American land. In fact, the entrepreneurs want their entire supply chain to be reservation-based. Already they buy all the wild rice for their meat stick products from the Red Lake Nation in Minnesota. Cranberries come from processors in Wisconsin that source from Native lands.

Long-term, the goal is to encourage startups on reservations and prepare existing Native American businesses to supply national customers. For now, they work to increase capabilities among their existing suppliers and spread the word through public speaking.

The company's more immediate impact is job creation. Native American Natural Foods employs 14 people, many with very little work experience. "We have guys selling to Whole Foods who had never even been in a Whole Foods store before," says Tilsen. "Doing this is a way to break the isolation of the reservation." Last year the business started down the road toward employee ownership.

Jessica Heart, a business assistant at Native American Natural Foods, is just the kind of person Hunter and Tilsen want to help. Heart, who grew up on Pine Ridge, has a high school education and five children. Until the company hired her two years ago she was unemployed. "Now I can buy my kids clothes and food and keep my family together," she says.

Heart says the company rewards her with more than just a living. "It's inspired me a lot," says Heart. "Sometime in the future I'd like to maybe own a business myself."