While the state Legislature has designated Bolinas Lagoon "a national treasure of extraordinary beauty," federal authorities have fixed a $2.5 million price tag on studies to determine how to preserve it and whether it is worth saving at all.

Scheduled to complete its "reconnaissance" of the heavily silted lagoon this month, the Army Corps of Engineers must now determine the environmental consequences of removing all that silt. Perhaps more challenging, the corps must convince Congress the cost is worthwhile.

To help the corps's case, the Legislature has urged the President and Congress to spend federal funds on Bolinas Lagoon, which it declared "one of nature's most magnificent, fragile wonderlands."

The joint resolution was introduced by West Marin's Assemblywoman Kerry Mazzoni, who presented it to county Supervisor Steve Kinsey and members of the Committee to Save Bolinas Lagoon at Stinson Beach last week.

"We do other resolutions," Mazzoni told spectators, "but this one means something. It has gone through committee and the legislative process."

Accepting the framed resolution of behalf of the county, which owns Bolinas Lagoon, Kinsey said there is "tremendous momentum" to see the project through to completion.

The county is expected to share the $2.5 million cost of the corps' investigation, which includes an environmental-impact study and feasibility studies based on computer-generated models of the lagoon, as well as a cost-benefit analysis of the project.

Half of the county's share can come from in-kind services, but the studies still represent a considerable expense for cash-strapped Marin. The Committee to Save Bolinas Lagoon is urging full federal funding instead.

Although the President's budget for the next fiscal year appropriated $240,000 towards the project, the Senate has offered only $750,000, said Clem Whitaker, one of the committee's chief lobbyists, who credited the influence of California's senators.

Urging committee members to pressure California representatives into matching the Senate's offer, Whitaker said, "There will be every effort to get Congress next year to cough up the money to see this project to completion."

The committee's chairman, John Jones, said the news from Capitol Hill was "a dramatic step forward and very strengthening." He added that Washington's budget process was "interesting" and "opaque."

Meanwhile, the corps is preparing to undertake a two- to three-year study of how removing the silt will affect the lagoon and its resident wildlife.

The study will be carried out in consultation with the lagoon's neighbors, which include the Point Reyes National Seashore, the Gulf of Farallones National Marine Sanctuary, Golden Gate National Recreation Area, Tamalpais State Park, and Audubon Canyon Ranch.

Finding consensus among all those organizations for an appropriate solution will take a while, but it is absolutely necessary to assure success, said Bob Nielsen, a Corps of Engineers planner.

Even more difficult will be appraising the value of a project that has no direct economic benefit, such as opening a navigable waterway would. "How much is a seal worth?" Nielsen asked rhetorically.

However, one of the reasons the joint resolution passed so easily was that many members of the Legislature know and appreciate the Marin Coast, Mazzoni said.

She said she hopes members of the Congress feel the same way, but planner Nielsen noted it is always difficult to get federal funds. "We propose and Congress disposes," he said. "There are a lot of competing interests."

However, "if we don't do anything," he added, "in five years, we could be looking at Bolinas Meadows."