For Marcia Barinaga, who studied biology and worked as a science journalist, Barinaga Ranch in Marshall represents a ripening stage in her career.

"I joke that I want to use my training in as many ways as possible," said Barinaga, who started milking her own sheep five years ago. "My training helps me with the animal husbandry and with my cheesemaking, which is all about microbiology and pH and chemistry."

Now tending a herd of 97 pregnant ewes due to give birth this month at the 800-acre ranch, Barinaga is one of the few cheesemakers on the North Coast who can claim family roots in curds and whey.

Her grandfather grew up in the Basque region of Spain and moved to Idaho in the early 1900s to work as a sheep herder. Her father, who now lives in Sonoma, grew up on a sheep ranch in Idaho before leaving for a career as an engineer.

While she still has cousins in the Basque country who make sheep's milk cheeses, the Basque shepherds working on the meat ranches of the American West lost touch with their dairying past.

"Sheep cheese in the U.S. is a very new tradition," Barinaga said. "For me, it was a full circle and very fulfilling."

The Barinaga Ranch will open its gates for a special cheese tour on March 22 to kick off California's seventh annual Artisan Cheese Festival in Petaluma. During last year's festival, the tour group arrived at the ranch just as one of Barinaga's ewes went into labor.

"I had 20 spellbound people in the barn for an hour and a half," Barinaga said. "For me, that's just another day in the month of March."

Year round, Barinaga offers tours of the ranch one Saturday a month, where guests can meet the ewes and lambs, watch a birthing or a milking, then taste the cheese.

After the lambing season is over, Barinaga will start milking and making a new batch of cheese in April. In October, the next round of breeding begins.

"Our cheese is very seasonal and it's very much an artisan product," she said. "In the summer, the cheese ages for three months before we sell any of it. ... Through the winter, we sell the cheese that is 6 to 9 months old."

Barinaga trained as a cheesemaker in Vermont and with her Spanish cousins. She only makes one kind of cheese, but it comes in two sizes.

The larger one is a 5-pound round called Baserri, which means "farmhouse" in Basque. Txiki, which means "little" in Basque, comes as a 1.5-pound round.

"They age differently and have different flavor profiles as they age," she said. "We've found that the Txiki ages really well, but it will tend to dry out faster."

The cheeses have already garnered lots of media attention, including a spread in Culture magazine and the cover of San Francisco magazine. Txiki won Best of Show at the 2012 California State Fair Cheese Competition.

The natural-rind cheeses, which have a nutty flavor and creamy texture, are available at Oliver's Market on Stony Point Road, Whole Foods in Petaluma and the Cowgirl Creamery in Point Reyes Station. Restaurants serving the cheeses include Park 121 in Sonoma, Bistro des Copains in Occidental and Osteria Stellina in Point Reyes Station.

At Park 121, chef Bruce Riezenman serves the aged Baserri with salumi, Marcona almonds and quince paste.

"It's such a beautiful cheese to eat unadorned," he said. "What I really like about her cheese is that it's her sheep and her milk."

Barinaga and her husband, Corey, bought the ranch in 2001 after spending weekends in the area since 1993. The land is between the Marshall-Petaluma Road and Highway 1, with a stunning view of the bay.

"We saw this ranch, and we fell in love with it," she said, adding that they lease much of the acreage to Bill Barboni of Hicks Valley Grass-fed Beef.

Once they moved full-time to the community, the couple wanted to do something with the land, which is part of the Marin Agricultural Land Trust (MALT). Their goal was to sustain the land's agricultural heritage as well as the economy of the community.

"We also wanted to be doing something that could economically sustain the ranch," she added. "And we're almost there."

Barinaga also sells fresh lamb to restaurants, plus sheepskins and wool blankets, breeding ewes and rams.

"It's a holistic operation," she said. "We try to use every part."

You can reach Staff Writer Diane Peterson at 521-5287 or diane.peterson@pressdemocrat.com.