By early spring, about 5,630 acres near the mouth of the Russian River could be open to the public, revealing redwood forests, wildflower meadows and flowing streams, home to rare birds and frogs.

That coastal prairie, overlooking some of the most photographed views of the Pacific Ocean on the California coast, could have been sold as 38 homesites. But the Sonoma Land Trust and other nonprofit groups, plus government agencies, collaborated to forge the single largest conservation land acquisition in Sonoma County, a $36 million agreement to buy the property, newly named the Jenner Headlands.

"It's a large, beautiful, intact landscape, one of the most scenic spots on the coast," said Ralph Benson, executive director of the Sonoma Land Trust, which will manage the property for up to a decade.

Once home to Kashaya Pomo settlements, then part of a Spanish land grant, the land is rich in natural and cultural resources, Benson said. "The place doesn't look much different than it did centuries ago, and it's more important than ever to seize these opportunities where you can protect lands that haven't been cut up into pieces."

On a recent winter day, standing on the ranchland east of Highway 1, one could look down on Goat Rock, Pomo Canyon Trail and Willow Creek. The light glimmered off the ocean, and layers of fog hung in the sky. And on clear days, visitors can see Point Reyes and Mount Diablo and can watch for migrating gray whales. Below, the Russian River hits the ocean, a favorite spot for kayakers as well as the harbor seals that give birth to pups there. The headlands property on the northern side of the river includes 1,500 acres of coastal prairie, 3,100 acres of redwood and Douglas fir, oak woodlands, native grasses and serpentine rock outcroppings. There are eight watersheds, including Jenner Gulch, Russian Gulch and Sheephouse Creek, all home to steelhead trout. State biologists have been reintroducing coho salmon into Sheephouse Creek.

Some of the wildlife of special concern living in quiet forests and along 8 1/2 miles of streams are northern spotted owls, burrowing owls, American peregrine falcons, ospreys and bank swallows. Now-rare California red-legged frogs, foothill yellow-legged frogs, California red tree voles and steelhead trout and coho salmon find safe haven here.

California Coastal Trail

One of the boosts to recreation will be construction of a 2 1/2-mile stretch of the California Coastal Trail. Some tours will begin after the deal is closed, expected in March or April.

"It's absolutely breathtaking to be on the heights and look down at the mouth of our river," said Petaluma veterinarian and environmentalist Bill Kortum. He once answered a call to treat a sick cow, and was told it was "on the back 40." The ranch was so big, he said, that the visit to the back 40 acres meant half a day's travel back and forth.

The purchase is particularly noteworthy because the ranch is adjacent to more than 13,000 acres of the Sonoma Coast State Park and conservation easements and will create more than 30 miles of a relatively unbroken stretch of preserved land from Bodega Head to Fort Ross.

The nonprofit and governmental groups have been working for four years with the sellers, Sonoma Coast Associates, Russian River Redwoods and Gualala Redwoods Inc., to put together the deal. In 2005, the owners came to Sonoma County Supervisor Mike Reilly saying they wanted to explore options for the property. In the early 1970s, they had developed a subdivision of 38 parcels to the north on what had once been part of the Rule Ranch. Reilly brought in the land trust, which brokered the deal.

The property will continue as a working cattle ranch that emphasizes environmentally sound grazing practices and restoration of forests, native plants and streams, land trust representatives say. Marshall Hendren, a local cattleman, has had the grazing lease for more than 30 years.

Putting up one-third of the money is the Sonoma County Agricultural Preservation and Open Space District, which benefits from a voter-approved 1/4-cent county sales tax. Money also comes from a state wildlife and park bond managed by the California Coastal Conservancy and the Wildlife Conservation Board. Federal National Oceanic and Atmospheric Administration and the Gordon and Betty Moore Foundation also are contributing.

Managing the property

The land trust couldn't find a public parks agency willing to manage the Jenner Headlands after the sale because of the state's strapped budget, and so the trust will own and manage the property on an interim basis for five to 10 years, said acquisitions director Amy Chesnut. The open space district will have a conservation easement on the property, and it and other funding partners will be involved in the property's protection and management until a public land agency is able to take title. The parties are raising a separate $4 million to use for operating costs. So far, they're $2 million short.

According to Dr. J. Ollie Edmunds Jr., chairman of Gualala Redwoods Inc., the area originally called the Muniz Rancho was created by land grant when California was a Spanish colony. In the 1860s, the John Rule family bought some of the property, and raised sheep and cattle for more than 100 years. The Rule family sold its holdings in 1960.

Edmunds, professor emeritus of orthopedic surgery at Tulane University School of Medicine in New Orleans, said he found his favorite spot on the ranch in 1962 when he was a student at Stanford University - Picnic Rock, shaded by wind-swept bay trees at the top of the coastal prairie overlooking the Russian River.

"From Picnic Rock, you can enjoy the view of the colorful wildflowers on the prairie and the Sonoma Coast from Russian Gulch to Bodega Head and Point Reyes. On a clear day, you can see the Farallon Islands," Edmunds said.

"I can envision Native Americans from the nearby village centuries ago sitting on these rocks as they fashioned arrowheads and enjoyed the same view."

E-mail Jane Kay at jkay@sfchronicle.com.

This article appeared on page A - 1 of the San Francisco Chronicle