Support for Sonoma County's regional parks has reached new heights, with significant increases in annual pass purchases, revenue from day use and donations to sustain operations.

The surge has been credited in part to a revitalized promotion campaign that's sought to rebrand county parks as part of a wider, popular network of local open space.

Officials said the result is that a park system described just two years ago in a county report as "somewhat outdated" and "invisible to the general public and its partners" is now drawing more users, volunteers and sponsors, including businesses, community groups and individuals.

"Our improved marketing strategy has paid off," said Regional Parks Director Caryl Hart, whose department oversees 49 parks, including trails and open spaces that encompass about 58,000 acres.

In a report last week to the county Board of Supervisors, Hart listed improvements made to that system in the past two years. She also detailed challenges that remain, foremost among them a $17 million maintenance backlog.

The list includes crumbling roads, eroded trails, old restrooms and other outdated infrastructure.

"It remains a problem for this department as well as those throughout the state and nation," Hart said.

The boost in user numbers and park revenue and influx of donations and volunteer work could make for a brighter trend, she said.

Park use shot up in the past year by more than a third to an estimated 5.1 million visitors.

Most popular are Doran Regional Park in Bodega Bay, Spring Lake Regional Park in Santa Rosa, Healdsburg Veterans Memorial Beach, Ragle Ranch Regional Park in Sebastopol and Riverfront Regional Park near Windsor.

The number of annual passes sold -- the county now calls them "memberships" -- was up 19 percent to 15,000 in 2011-2012, generating just less than $800,000. Day-use revenue in 2011-2012 increased by 29 percent to just more than $1 million.

Factors included a $1 increase in day-use fees to $7, tiered fees and a longer season for campgrounds, a gift card campaign for park memberships and new attractions, including Lakeside Grill now at Spring Lake and a summer water carnival at Healdsburg Veterans Memorial Beach.

Food trucks also have been brought in to Spring Lake and Ragle Ranch on weeknights to help attract visitors.

"That model is going to be rolled out into other parks," Hart said of such business ventures.

Additional support has come from the nonprofit Sonoma County Regional Parks Foundation, which in the past year gave nearly $400,000 to support park programs and capital projects, including $200,000 toward renovation of the historic Watson School in Bodega.

The foundation also helped raise more than $200,000 to keep Annadel State Park open under a temporary operating agreement with the county.

To boost the number of paying visitors to Annadel and adjacent Spring Lake, the county in November or December will propose charging for parking on Channel Drive. Many users now park on the road to avoid being charged.

"It's a little bit of a stick attitude, but it needs to happen," county Supervisor Shirlee Zane said of the change. "We all need to pay for these parks."

County park operations have suffered a nearly 40 percent drop in spending from the county's general fund in the past four years. Part of that drop was because the county veterans buildings were transferred to non-governmental operators.

General fund spending on parks is not expected to rebound in the near term, and the department is under orders to steadily increase the share of its budget that comes from park fees, charges and concession revenue. Altogether, they now account for three-quarters of the $18.7 million annual budget.

Another potential money source -- a tax measure to boost local park budgets -- is not being explored because of a state parks scandal over secret surplus funds, Hart said.

Donations will remain the go-to source for funding capital projects, including maintenance, Hart said.

Those projects include repaving the Doran Park entrance road and campground loops, remodeling the Environmental Discovery Center at Spring Lake, overhauling the water system at Tolay Lake and renovating trails, restrooms and signs throughout the system.

The board directed Hart to return in January with a prioritized list of maintenance projects. She also plans to ask the board to allow her department to draw up a parks blueprint for the entire county, looking at the current and future network of city, county and state parks and open space. Estimated cost for that plan is $250,000.

"The next step for us is to bring in the public and develop that missing piece," Hart said of the parks blueprint. "We have world-class assets. Now is the time for us to step up and become the world-class park system that we have in this county."

You can reach Staff Writer Brett Wilkison at 521-5295 or brett.wilkison@pressdemocrat.com.