Instead of merely admiring the graceful beauty of the Golden Gate Bridge or taking a stroll across the international landmark, visitors could soon explore its off-limits undersides, climb on its cables or ride elevators to the tips of its towers.

Bridge officials, tired of having to raise tolls and transit fares to cover recurring budget deficits, want to add an interactive experience and a history center to the tourist attraction in hopes of getting visitors to leave more of their wallets in San Francisco.

The project could generate as much as $9 million a year, according to early estimates given by the Golden Gate Bridge, Highway and Transportation District. The district faces an estimated $132 million deficit over the next five years.

"We want to offer an experience where people can go out on the bridge and experience something that's not available to the public," said Mary Currie, spokeswoman for the bridge district. "If we can come up with something that would be a real educational experience, and something fun and exciting, it will benefit our toll-payers."

The model for the Golden Gate Bridge experience is the Bridge Climb at the Sydney Harbour Bridge, where visitors pay about $200 for a guided trek along catwalks, up and down ladders and along the outer arch of the coat-hanger-shaped bridge.

Bridge officials say they have not yet determined what type of participatory activity would be offered at the Golden Gate. It could be a tour of the bridge's understructure, along catwalks dangling high above the water. Or it could involve a climb up the bridge's sweeping cables, though their steepness might make it impractical as an activity marketed to the masses. Currie wouldn't rule out the possibility of elevator rides to the tower tops, but said that might interfere with maintenance.

Bungee jumping, however, is out.

"It's not going to become an amusement park," she said. "That would not be in keeping with the icon of the Golden Gate Bridge."

People who help direct visitors to San Francisco tourist attractions said they hadn't heard of the plan, but expected it would be a big hit.

"People are so captivated by the Golden Gate Bridge," said Angela Jackson, a spokeswoman for the San Francisco Convention & Visitors Bureau. "There is definitely a market for it and a clientele for it."

A top attraction

Charlotte Stengel, a concierge at the Fairmont Hotel, said the Golden Gate Bridge is one of the top attractions tourists ask about.

"This would definitely be popular," she said.

The nature of the attraction, and where it would take place, will be part of the proposal process the bridge district started Tuesday. At this point, the district is seeking statements of interest and qualifications from firms that have done similar projects on public property and have experience dealing with government agencies, Currie said. The Australian firm operating the Sydney bridge walk is one such company, she said, and a Buffalo company that runs a program at the Houston Space Center is another.

The attraction would need to fit in with the bridge's maintenance, satisfy safety and security concerns and be unobtrusive to motorists, Currie said. It will need to be educational, tie in with a new interpretive area being built with a National Science Foundation grant, and include a visitor center. It would probably take three to four years to set up the attraction, she said. Logos and large signs would be prohibited, Currie said, acknowledging the response to an unsuccessful 2007 proposal to seek corporate sponsors that would have been able to display corporate logos near, but not on, the bridge.

No advertising

Bridge fans, including San Francisco Beautiful, fought that proposal, saying that it would open the pristine landmark to the adulteration of corporate advertising. Sheila Kolenc, interim executive director of the organization, said the group wouldn't object to this proposal as long as signs and on-site advertising are sparse.

"Getting people outside to see the views of the bridge and get some exercise is something we would support."