Fourth of July revelers filed down to San Francisco’s Northern shore — jockeying for early vantage points to watch the evening fireworks. But what used to be the prime spot for firework viewing, the old municipal pier, was gated off. A sign in front read "Muni Pier Closed" for the 4th of July holiday.

The decaying 85-year old concrete pier has deteriorated to a point that National Park officials worry about allowing crowds onto it, even though it’s open for walkers and bicyclists the rest of the time.

“It’s safe to come out here and walk and bike,” said National Park Ranger Lynn Cullivan, “but if we were to get a few thousand people out here we’re not sure it could handle it.”

Just in front of the pier’s padlocked gate, Keith Breitbach and two others stood before a table with a banner reading “Save the Aquatic Park Pier,” engaging anyone who would stop to relay just what a sorry state the pier is in.

“As you walk out you’re going to see it’s really kind of crumbling,” Breitbach told a group of visitors. "It’s a state of desperation right now."

The pier, which is part of the Maritime National Historic Park has been crumbling over time — now to the point large swaths are fenced off to the public. Rusted, exposed rebar is visible through chipped concrete and in some places gaping holes reveal the bay waters beyond.

“It’s going to potentially be shut down to the public -- public access will be limited,” Breitbach said. “Once we lose access to the pier, we will lose the pier entirely.”

A recent survey of the pier pinned estimates for its replacement between $60 to $80 million — money —the Federal government says it does not have. So Breitbach and the new Save Aquatic Park Committee are trying to raise public awareness of the issue, and in the meantime lobbying local and Federal political leaders to try and raise the funds.

“Our mission is really to preserve the best of our past and protect it for future generations,” Breitbach said clutching a clipboard.

On a recent day when the pier was open to the public, throngs of visitors traversed its long promenade by foot, bicycle and Segways, taking in sweeping views of Alcatraz, the Golden Gate Bridge and the bay. Breitbach stood at the pier’s entrance painting a grim picture for visitors — urging them to sign a petition calling for its saving.

“Take a look at the pier,” he told one group. “When you go out there, come back and tell me what you think.”

“It’s rough, it needs a lot of TLC,” visitor Jennifer Showalter Perez reported back. “It would be worth the restoring of it so that everybody, generations to come, can enjoy what is out here.”

The National Parks Service is expected to soon conduct another study to try and narrow down the price tag for a replacement. Breitbach said he is hopeful someone in congress will champion the project.

The pier serves more than just a place to take in spectacular views. It also creates a protective cove where swimmers can swim in the bay without the blustery currents.

“If we’re out there without that pier you basically get swept out into the bay,” said Reuben Hechanova, president of the Dolphin Club.

Park officials said they were happy to get the support of the Save the Aquatic Park Committee — and applauded the citizens’ group efforts to raise awareness and funds.

“It’s their pier,” Cullivan said. “I just think the more people are interested — the more people know — the better it will be.”