It's an unsettling and expensive trend.

Floodwaters caused $4 million in damage to Whitewater State Park in 2007. High winds flattened more than 7,000 acres of trees and wrecked buildings at St. Croix State Park in 2011. Another massive flood last month hammered Jay Cooke State Park and the adjacent Willard Munger State Trail. And last week, 80-miles-per-hour winds damaged Itasca State Park and LaSalle Lake State Recreation Area.

"It's certainly an unusual pattern,'' said Courtland Nelson, Department of Natural Resources parks and trails director. "It's the second year in a row to have epic storms come through [and damage parks]. The most important thing is we haven't had anyone hurt. It's just astounding.''

Officials don't have damage estimates from this summer's storms, but they say it will cost millions of dollars. Now they have to figure out how to pay for it.

Federal disaster aid is likely to pay for 75 percent of some projects. A special legislative session this summer to consider aid for northeastern Minnesota infrastructure will include requests for money for the Department of Natural Resources, said DNR Commissioner Tom Landwehr. And the DNR may be going hat-in-hand to the Legislature next session, too, for repair dollars.

One of the biggest DNR projects will be repairs at Jay Cooke, where an iconic 1930s-era swinging footbridge was destroyed and where the Munger trail -- a popular paved bike route -- was severely damaged between Carlton and Duluth.

Nelson said the trail alone will cost millions to repair. "It's very steep, and it's 25 years old. We had at least 10 major culvert failures,'' he said. The last single culvert failure cost $1 million to repair.

"We'll have to go to the Legislature for funds,'' Nelson said. He said there's virtually no chance the DNR would abandon that stretch of trail because of the high price tag.

"I don't think that will happen," he said. "We get a ton of traffic on it, and I think there'd be a lot of support locally to get that rebuilt.''

Nelson said the DNR is likely to erect a temporary bridge across the St. Louis River until it determines how to rebuild the bridge at Jay Cooke -- and how to pay for it. The bridge provides foot access to about half the park, including 30 miles of trails. He said it could take a couple of years to repair.

Access road also damaged

The state Highway Department, not the DNR, is responsible for repairing Hwy. 210, which provides access to Jay Cooke. The highway was severely damaged. Officials estimate it could cost up to $40 million to repair the 8-mile stretch of highway through the park. The park, the state's ninth most visited, is expected to be closed until October, which will cost the DNR about $175,000 in lost revenue.

North Shore state parks received little damage in the June deluge, when up to 10 inches of rain fell. But the DNR's fish hatchery at French River northeast of Duluth and a fish trap at Knife River were damaged by floodwaters last month, Landwehr said. "The fish trap blew out completely," he said. "I don't know if we'll replace it.''

The damage last week at Itasca State Park and LaSalle Lake recreation area, just north of the park, weren't as severe. Crews worked to clear blown-down trees at La Salle, and it remained closed. Itasca is open.

The state is self-insured, meaning if a park building is severely damaged or destroyed, the state must pick up the tab. The DNR budgets money for routine repairs and maintenance but not for major projects like replacing structures or bridges, Nelson said.

Storm damage is part of doing business in the outdoors. But the rash of recent storms and damage inflicted has been frustrating, Landwehr said.

"We lost $3.5 million in revenue last summer because of the [government] shutdown,'' he said. Then came the storm at St. Croix State Park, one of the state's most visited.

And now two more storms this summer.

"It's demoralizing for staff to be dealing with cleanup and emergencies and not running parks like they'd like to, but I'm proud of how they've been dealing with it,'' Landwehr said.