FOR more than two centuries, its fog-shrouded forests and Spanish Colonial walls have been home to the oldest continuously operated military base in the nation. It is the guardian of the Golden Gate, an oasis of cypress and eucalyptus at the northwest corner of urban San Francisco.
But since the closure of the base here in 1989 and the departure last month of its main tenant, the Sixth US Army, the noble Presidio has become a costly albatross around the neck of the National Park Service.
Already strapped for funds, the park service cannot afford the Presidio's yearly budget. At $40 million - the most expensive park in the entire national system - it's more than double that of Yellowstone. The service doesn't have the resources or people to maintain the site's 870 buildings, 510 of which are considered historic treasures.
So the fortress that has flown the flags of three nations and sheltered troops through both world wars, the Civil War, and the Spanish-American War, is now itself struggling for survival.
The battle over the Presidio is one that has reverberated from San Francisco's city hall to the corridors of Congress.
At one point last spring, the Senate considered hawking the prime real estate to private developers, so the federal government could pocket an estimated half-billion dollars. San Francisco Mayor Frank Jordan turned down another proposal that the city take over park ownership. He argues that the Presidio is a national responsibility.
The House of Representatives apparently agrees. It has come up with a novel rescue plan. No one is sure yet that this plan will work, and it has already drawn some criticism from San Franciscans. But if it does work, it may hold lessons for other conservation efforts across the country in a era of dwindling public resources.
Last month, the House passed a bill creating the Presidio Trust, a unique government-corporate partnership plan with strong bipartisan support. A Senate version of the law, sponsored by Sen. Barbara Boxer (D) of California, is expected to come up for a vote later this month and has the backing of the Senate leadership.
To many, the House vote for the Presidio Trust by a 3-to-1 margin is remarkable. The Republican-led Congress approved an innovative spending plan at a time when federal downsizing is a priority and moves are afoot to create a commission to shrink the national park system. And, Presidio supporters note, the GOP House passed an environmental bill sponsored by a liberal congresswoman from a traditionally liberal city.
''The victory for the Presidio can be seen as a model of bipartisan cooperation, of public-private cooperation, a model for the rest of the country on how to create another revenue stream to fund parks,'' says Rep. Nancy Pelosi (D) of California, who authored the House bill and spearheaded the campaign to pass it. ''But the Presidio is so exceptional, I hope it doesn't raise expectations for other parks too much.''
While some Republicans in Congress continue to push legislation that threatens park funding, advocates note that preserving national parks is not a strictly partisan concern.
''We must remember that the values of national parks don't change very much, the pressures on them change,'' says Michael Alexander, chairman of the Sierra Club Presidio Task Force. ''It's become increasingly difficult to find ways to save the places that are truly part of our national heritage, places we need to set aside for our children and children's children.... The Presidio Trust is a creative way of trying to save one of the most stunning places on earth.''
Part of the Golden Gate National Recreation Area, the largest urban park in the world, the Presidio is an indisputably magnificent expanse of 1,480 acres.
The park includes 800 acres of open space surrounded by beaches, sand dunes, and coastal bluffs with panoramic views of the Pacific Ocean, the Marin Headlands, the Bay islands, and the San Francisco skyline. A 300-acre forest of eucalyptus and cypress trees contains miles of secluded hiking trails and a stunning golf course on the Bay.
Strategically located on the southern side of the Golden Gate, the Presidio was first claimed for the king of Spain in 1776. It was the most remote military post in the Spanish empire until 1822, when the newly independent Republic of Mexico took over the base. The United States has held the Presidio since 1846, when it declared war against Mexico to acquire northern California.
San Francisco owes its development to the strategic value of the Presidio, says Tom Adams, Washington representative for the National Parks and Conservation Association. ''It allowed the city to grow up around it and, because of its deep and narrow harbor, it was impossible for a foreign country to come in and take the city by force. As a result, the historical and cultural significance of the Presidio on the development of the nation as a whole, and the role San Francisco played in it, is enormous.''
Hundreds of military relics, homes, and historic sites dot the landscape: 17th century bronze cannons, ancient artillery batteries, pistol ranges, and stables. The barracks here housed soldiers during the Civil War and sheltered Indian fighters after the war ended.
''All kinds of events that have shaped this nation have passed through the Presidio,'' says Amy Meyer, co-chair of People for a Golden Gate National Recreation Area. ''For centuries it was the western entrance to the United States, the center of the West Coast. It is a place of such history and such moment - it must be preserved.''
But the cost of keeping up this historic park is enormous, and many see the Presidio Trust as the key to its survival.
The Presidio Trust legislation aims to ''merge economic reality with park stewardship.'' It sets up an independent trust corporation that would lease out 6-million square feet of rentable buildings to nonprofit cultural and environmental groups to reduce park operating costs. The park service will manage the beaches along the coastline.
Federal financing would amount to $50 million over the next five years, with decreasing levels of funding until the park reaches 80-percent self-sufficiency in seven years and total self-sufficiency in 12. A presidentially-appointed board would control the trust.
To secure Republican support for the trust, Representative Pelosi was forced to make concessions, most notably to Rep. James Hansen (R) of Utah, chairman of the House subcommittee overseeing national parks. Although Pelosi will not address specific criticisms, she hopes that concerns over the House bill will be remedied during Senate negotiations.
One of those concessions is the 12-year deadline for self-sufficiency, which is considered too short a period to get the Presidio up to code and fully self-sustaining, says Robert Chandler, manager of the Presidio. A longer deadline would help encourage lenders to invest in the park, he says.
Park advocates are troubled by the concession because the Presidio will revert to the Department of Defense for disposal if the trust is deemed to be failing. The criteria for failure are unclear, however. If the trust fails, the city of San Francisco would have the first right to acquire the park - an unlikely prospect.
Another major concession was to remove the park from the Interior Department and the National Park Service and instead make the trust accountable to Congress. While environmentalists prefer the department's oversight, ''Congress doesn't trust the park service to manage the Presidio,'' says Brian Huse, Pacific Region Director of the National Parks and Conservation Association.
The bill's concessions have some locals up in arms. The San Francisco Bay Guardian newspaper wrote that Pelosi ''has given away the Presidio to private interests.'' It argues for a 'wait and see' plan: Let the park service come up with a low-budget program for maintaining the park in the short term.
Park advocates say such criticism is unrealistic. ''No other unit within the park system has as many challenges to overcome in terms of rehabilitation and maintenance as the Presidio. Given that fact, it's safer to get the trust in place than allow the continued degradation of the park's resources so that no one will want to fund the Presidio or will have the money to fund it,'' says Huse.