Marina General Manager Janet Folk said the closure was devastating for her business, costing more than 90 percent of expected revenue for the last two weeks.
The marina was allowed to remain open during the shutdown, but since the lake itself was off limits, it was unable to use any of its 23 rental boats, which rent from $25 an hour to more than $500 a day.
None of the 300 full-time boat owners were allowed on the lake either, meaning the marina lost sales of fuel and supplies to those customers.
"We will not be able to make that up," she said, though fishermen had returned to the lake within hours of the end of the shutdown.
The marina ended contracts with most of its seasonal workers early because of the shutdown and put the five full-timers on half-pay. None of those workers will receive back pay, she said, since they are private employees not government workers.
Other federal recreation facilities in the North Bay reopened on Thursday as well, including the Army Corps' Bay Model Visitor Center in Sausalito.
The Point Reyes National Seashore reopened for normal business Thursday morning, including all trails, parking areas and campgrounds, spokesman John Dell'Osso said.
There are a number of academic and non-profit research projects in the park that resumed and it did not appear that any major experiments were damaged by the shutdown, he said.
Park staff was in the process now of contacting outside businesses that work at the seashore and contractors who work on park facilities. Those operations should resume in a matter of days, he said.
Federal offices were open in Santa Rosa, including the Internal Revenue Service and federal probation facilities, and there was a steady stream of people coming in, many apparently interested in paying their tax bills.
Richard Hill, a retiree from Bennett Valley, was headed in to make a quarterly tax payment. It had been due on Oct. 1, the day the shutdown began, so his payment was 16 days late.
"I'm not expecting any penalties, but I am going to fight for it if they do," he said.
Architect Allen Tillman agreed as he headed in to settle up a back tax bill.
"I think there should be some kind of a credit for the days they were not open," he said.
Tillman expressed intense frustration with the government shutdown.
"I just feel like the people who are running our government should be penalized - their individual paychecks," he said. "They should be fired, really. They are not doing their job."
Scott Doughtie of Santa Rosa, who returned to his federal job today in San Francisco, said the mood among his co-workers was positive as they set out to catch up on more than two weeks of lost work time.
Doughtie is an enforcement supervisor for San Francisco district office of the Equal Employment Opportunity Commission, which enforces a number of federal civil rights laws, including the 1963 Equal Pay Act, the 1967 Age Discrimination in Employment Act, and the 1990 Americans with Disabilities Act.
"We're going to have to work hard to catch up, but it's not insurmountable," he said.
Doughtie said that during the furlough period, his wife worked four days doing temporary accounting jobs and some catering work.