Nearly every state park in the Bay Area — from the towering redwoods at Big Basin to Angel Island, Mount Tamalpais to Mount Diablo and every state beach from Año Nuevo in San Mateo County to Big Sur — would close as part of budget cuts proposed by Gov. Arnold Schwarzenegger.

In all, 220 of California’s 279 state parks, about 80 percent, would be padlocked starting as soon as Labor Day, under details of a historic closing plan released Thursday night by the state parks department.

“We’ve never been in as serious a predicament as we are facing right now. It is potentially devastating,” said state parks spokesman Roy Stearns.

Layoffs could hit 1,500 or more of the 2,900 state parks employees, Stearns added.

“This is a clear indication of the absolute seriousness of the state budget deficit. We have driven to the cliff and some would argue we are already falling off the cliff.”

On Tuesday, as part of an effort to close the state’s $24 billion deficit, Schwarzenegger unveiled a series of proposed cuts. They included a plan to eliminate $70 million in state general fund money to parks in the year that ends in June 2010 and $143 million of that funding by June 2011. The latter number represents 40 percent of the state park system’s $387 million operating budget.

In effect, the plan would phase out all general fund support of parks, leaving them funded only by entry fees, camping fees, and various small taxes, such as a tax on fuel for off-road vehicles.

The proposal still must be approved by the state Legislature.

But Friday, Democratic leaders said the budget hole is so great they expect some parks will close. The main reason: Sales tax, income tax and other revenues flowing into Sacramento have collapsed during the economic downturn and Republican leaders have said they will not support any increase in taxes or fees.

“I’m going to work hard to keep them open, but not at the expense of things like insuring 1 million children in the Healthy Families program,” said state Sen. Fran Pavley, D-Santa Monica, who chairs the Senate Natural Resources and Water Committee.

Pavley said she will examine raising entry and camping fees, closing some parks in winter, partnerships with nonprofit groups, a new tax checkoff box on state tax forms, and other ideas to help reduce the number of parks closed.

Other parks on the closing list include Henry W. Coe State Park near Morgan Hill, which at 90,000 acres is the second largest state park in California; Sutters Fort and Marshall Gold Discovery sites; Humboldt Redwoods; Anza-Borrego Desert; Bodie ghost town; Pfeiffer and Andrew Molera state parks in Big Sur and the popular Lake Tahoe parks of Emerald Bay, Kings Beach and Sugar Pine.

The 59 that would remain open are parks that raise enough revenue to at least break even, such as Hearst Castle or Asilomar, a conference center in Pacific Grove, or places like San Luis Reservoir, Folsom and Oroville, which are supported by fees such as boating taxes.

Environmental groups already have begun to collect signatures on petitions and draft letters to legislators. A rally is planned at 5:30 p.m. on Monday at Santa Cruz’s Natural Bridges State Beach — one of the parks slated for closure — by Friends of Santa Cruz State Parks.

“We are taking this proposal incredibly seriously. The Legislature and the governor seem completely committed to passing a revised budget by July 1. That means we have less than a month,” said Elizabeth Goldstein, president of the California State Parks Foundation, a nonprofit advocacy group.

Goldstein noted that a study by the University of California-Berkeley found that for every $1 in public money spent on state parks, $2.35 is returned to the state in taxes from tourism and other revenue they generate.

A basic problem is that is nearly impossible to “close” a state park or beach.

“We’ve never closed a park. We only close them at night,” said Gary Strachan, supervising ranger at Año Nuevo State Reserve near Pescadero. “If it means locking bathrooms and closing a gate, I guess that’s closing a park. But through 30 years of experience, knowing the public, visitors always try to get into the park.”

When his park’s famous elephant seals began arriving in the 1970s, Strachan said, there were no regular rangers. After a story about the seals ran in Sunset magazine, visitors began descending on the area without supervision.

“It was a nightmare. People were getting bitten and chased. Pups were getting harassed,” Strachan said.

If the parks close, a small crew of rangers would patrol wide areas, checking in on closed parks. People still would park on highways and walk to beaches. But rangers, park managers and legislators are worried that with almost no supervision across 1.5 million acres of parklands, it is almost certain there will be vandalism, animals poached and a high risk of wildfires from trespassers.

Because there are thousands of camping reservations already booked for the summer, Stearns said, parks won’t close until after Labor Day. Public outcry could affect the outcome. Last year, Schwarzenegger proposed closing 48 parks, then backed off when the public lit up Sacramento switchboards.

“My office got more calls on the parks closures than any other issue about the budget,” said John Laird, a retired state legislator who was chairman last year of the Assembly Budget Committee.

Laird wrote a proposal to increase vehicle registration fees by $10 a year, which would have raised $260 million for state parks. All California residents would have been given free entry. Montana has a similar plan already in place. The idea passed the Assembly, but died when then-Senate President Don Perata killed it in an attempt to find compromise with Republican leaders on wider budget issues.

Laird said environmental groups could put the fee on the 2010 ballot.

“I think that’s a very creative idea, and certainly worthy of discussion,” Pavley said.

Contact Paul Rogers at progers@mercurynews.com or 408-920-5045.