In a blow for preservationists, the Bush administration has declared once and for all that it will not intervene in local efforts to save the scenic Gaviota coast.

A year ago, at the conclusion of a three-year, $150,000 National Park Service study, the wild canyons and historic ranches of the Gaviota coast from Coal Oil Point to Point Sal were deemed rare and worth saving -- the longest stretch of rural coastline left in California.

Because of landowner opposition, the Park Service declined to designate the coast as a national seashore or reserve, but suggested ways that the community could take better advantage of federal funding to protect the land.

Last week, Craig Manson, assistant secretary of the Department of the Interior, backed away even from those ideas.

In a March 5 letter to the U.S. Senate and House of Representatives, Mr. Manson stated, "There is no new federal action envisioned or recommended and no action is required by Congress."

Local efforts to protect the Gaviota coast have "set a fine example for other parts of the country" and should be allowed to continue "without further National Park Service involvement," he said.

Rep. Lois Capps, D-Santa Barbara, who pressed Congress in 1999 to authorize the study, expressed dismay at the final word from the Bush administration.

"I am extremely disappointed," she said. "The administration dropped the ball by not making any recommendation on steps to ensure that a wild and undeveloped Gaviota will be around for our grandchildren to enjoy. There will be no help and no funding from the federal government for an area that the Park Service itself has declared nationally significant. That is a shame."

At the same time, Rep. Elton Gallegly, R-Simi Valley, was pleased that the Department of the Interior "acknowledged the environmental stewardship of the local community and Vandenberg Air Force Base," said Tom Pfeifer, a spokesman for the congressman.

Mr. Gallegly circulated a letter in Congress in 2002 against a park designation for the Gaviota coast, saying it would endanger national security because it would include Vandenberg Air Force Base.

The Interior Department's decision places the fate of the Gaviota coast firmly in the lap of a divided Santa Barbara County Board of Supervisors.

Brooks Firestone, a Santa Ynez vintner who was recently elected to the board, is expected to be the swing vote. On Tuesday, Mr. Firestone noted that, as a state assemblyman, he had supported the Park Service study of the coast.

One way to preserve land there, he said, is to allow owners to build a few homes if they agree to set aside large parcels in open space.

"Instead of holding the line by zoning, that maintains the land in open space in perpetuity," Mr. Firestone said.

The concept of a national seashore on the Gaviota coast first arose here 10 years ago, at a conference organized by the local chapter of the Audubon Society.

Despite the setbacks of the last 12 months, members of the Gaviota Coast Conservancy, a nonprofit group that was formed in 1996, said they would wait for another administration and try, try again.

After all, they said, there is only one national seashore on the West Coast -- a 35-mile-long stretch at Point Reyes -- while the East Coast has nine national seashores.

"A lot of things can change," said Mike Lunsford, the conservancy president. "We certainly aren't going away. We're going to continue to be the advocates for permanent protection of the coast."

In addition to about 100 landowners within the study area, the opponents of a national park designation for the Gaviota coast included the Cattlemen's Association; California Farm Bureau; Lompoc, Buellton and Goleta Valley chambers of commerce; cities of Buellton, Guadalupe, Lompoc, Santa Maria and Solvang; and county supervisors Joni Gray of Orcutt and Joe Centeno of Santa Maria.

The Hollister Ranch Owners Association, a leading opponent, provided funds to hire a lobbyist in Washington, D.C.

"The Hollister Ranch wants to commend the Park Service and Department of the Interior in acknowledging the local community's commitment to the ongoing preservation of the Gaviota coast," said Andy Mills, a spokesman. "The Hollister Ranch feels that the community is fortunate that the Gaviota coast has been spared the growth-inducing impacts that a National Park designation could bring."

The American Land Rights Association of Battle Ground, Wash., having helped stop dozens of new national parks around the country, also joined the fray.

"If it ain't broke, don't fix it," Chuck Cushman, the executive director, said Tuesday. "The government doesn't have to own all the nice places in this country."

Mr. Cushman said the people of Santa Barbara County were better off without a national park on the Gaviota coast, with gates, rules, road closures and wilderness areas off-limits to the public.

"It was a solution in search of a problem," he said. "You're not likely to see any mass developments that are going to tear apart the viewsheds there."

In fact, the conservancy is fighting several proposals for homes on the coast, including 55 at Naples, two miles west of urban Goleta; a 15,000-square-foot estate west of Refugio State Beach; and the expansion of the county's Tajiguas landfill.

The high cost of purchasing land on the coast for open space is staggering and makes federal funding imperative, Mr. Lunsford said.

"People on all sides have been saying they want to see the Gaviota coast remain the same," he said. "Permanency usually boils down to the purchase of land or development rights. It means dollars. It's not prudent to turn our backs on federal assistance."