Think of American wine, and the vineyards of California will most likely come to mind. But as of 2002, each of the 50 U.S. states has some sort of winemaking industry. The Great Plains state of North Dakota, best known for growing grains like wheat and barley, was the last state to open a winery. Now the state is home to two of them.

The Maple River Winery is in tiny Casselton, North Dakota. When it opened its doors 2 ½ years ago, winemaker Greg Kempel says, "All of our friends in Casselton said, 'Who will visit a winery in a small town in North Dakota?'"

Lots of people it turns out. Greg says he and his wife Susan have had visitors from all 50 states and around the globe come to their vineyard. Some, he says, come out of curiosity. "We have had so much publicity from all over the world. Mention North Dakota wine and it catches everybody by surprise."

Business has been so good, that Greg and Susan Kempel had to install five new fermentation tanks in what used to be their tasting room. Now tastings are held next door at a pizza parlor.

Don't expect to find the kind of wines at Maple River Winery that you'd find in California's Napa Valley. "We can't grow grapes like California can," Greg Kempel says. "They have cabernet, chardonnay grapes. They won't survive in North Dakota. We have that little niche, where can make fruit wines with fruit that is native to the prairie or state. California is wine country, but they don't have rhubarb wine or chokecherry wine."

Other flavors of wine produced by Maple River Winery include wild plum, country crabapple, apricot, and apple blended with mint or jalapeno peppers. The fruits are harvested by "people from all across North Dakota," Greg Kempel says. "Three different groups bring fruit in. Stay-at-home parents, who farm or take the kids out and bring the fruit in. Retired people, or people who are looking for second incomes. And organizations like churches and museums that are looking for a fundraiser."

Mr. Kempel says the fact that so many growers and gatherers contribute to their product is one of the things that make Maple River Winery special.

Scott Stoffrahn, who works for North Dakota Senator Kent Conrad, agrees. "With a lot of people bringing in product, it makes micro agriculture possible in North Dakota, which is really important."

Important, because agriculture is North Dakota's leading business, and traditional agriculture has become too expensive for some farmers to pursue. The state has been looking for ways that farmers can earn more dollars per hectare. Winemaking is one way to do that.

Greg Kempel says it's also a way to use untapped resources. "All of this fruit coming into the winery used to go to waste and we're creating a new market for it."

In addition to making wine from native fruits, he is looking for wine grape varieties that will grow in North Dakota with help from farmer Rodney Hogen, who has farmed soybeans and corn for several years.

"I didn't even know you could grow grapes in North Dakota," Mr. Hogen says. But now, three years after Greg Kempel asked him to grow grapes on his farm, Mr. Hogen is growing 11 varieties.

It's still very experimental and the grapes only amount to about 1% of his crop, but he's already opened a visitor's center and tasting room at Red Trail Vineyard, and he has even bigger plans.

"This is something new. A lot of people wouldn't want to do this, but we saw a niche," he says. "We're close to Fargo, we're close to the interstate. We want to do a restaurant out here, too."

People like Rodney Hogen and Greg and Susan Kempel are creating a whole new industry in North Dakota. Their timing is good. A poll conducted this summer by the Gallup Organization indicates that for those Americans who drink alcohol, wine has become the drink of choice.