PORTLAND – Maine’s failure to maintain and upgrade its state parks and historic sites has left a repair backlog totaling more than $33 million, according to a new study and policy paper prepared for the Baldacci administration.

Among the signs of neglect are crumbling buildings, outdated restrooms and limitations on access for disabled visitors.

The condition of the parks is seen as part of a broader failure to invest in Maine’s “green infrastructure,” which includes recreation lands and trails, beaches, fish hatcheries, boat ramps, farmland and forests.

By one measure, according to the study, the state needs $85 million to preserve and expand those resources over the next two fiscal years.

The case for such spending will be put forward June 29 in Augusta at a daylong forum sponsored by the Governor’s Steering Committee on Maine’s Natural Resource-based Industry. The forum, called “Sustaining Maine’s Green Infrastructure,” is designed to give rise to a coalition of boaters, hunters and other interest groups looking to advance the effort.

Advocates say public spending on natural resources has lagged far behind demand, despite their key role in Maine’s economy. State parks generated more than $95 million in economic activity last year.

More than 2 million people visit state parks and historic sites each year, but such facilities have drawn little support in the Legislature and at the polls. Over the past 35 years, voters have approved only $8.5 million for capital repairs.

“We’re not crying wolf,” said Pat McGowan, the state’s conservation commissioner. “This is a great resource that not only needs protection, but needs infrastructure improvements.”

The policy paper prepared for the forum by the State Planning Office said parks will have to grapple with a backlog of problems with septic systems, water supplies, handicapped access, asbestos removal and playgrounds.

“Facilities are below standards and reflect poorly on Maine’s tourism image,” the paper says. “For example, some heavily visited areas still lack running water.” The paper says one unidentified visitor described the toilets as “Third World stuff.”

Historic sites are falling victim to neglect and weather. Fort Popham poses a safety hazard to visitors and access is restricted. Katahdin Iron Works, built in the 1840s, is crumbling and could collapse. The 1839 blockhouse at Fort Kent contains asbestos.

“They’ve just been allowed to deteriorate over time,” said Jody Harris, director of program services at the State Planning Office. “We spend energy and money trying to buy new resources, but not enough on maintaining what we have.”

Maine’s General Fund, which has suffered budget cuts, provides most of the money for maintaining parks and historic sites. Revenue from loon conservation license plates, 60 percent of which goes to park maintenance, has been falling since 1999.

Richard Barringer, the former state conservation commissioner who chairs the steering committee that’s sponsoring this month’s forum, said upgrades to state parks are essential if Maine hopes to grow its economy by promoting outdoor attractions.

Barringer said he hopes the future of Maine’s parks and green infrastructure becomes a topic for discussion during this year’s gubernatorial campaign.

“The state should see these as strategic investments and not just a drain on the public purse,” he said.