THOMSON -- Standing on the precipice of a massive washout along Minnesota Highway 210, and in front of the twisted remains of the landmark Swinging Bridge, state officials on Tuesday outlined early plans for repairing damage caused by last month's flooding at Jay Cooke State Park.

They spoke during the first official media tour of the park since heavy rain raised the St. Louis River to record levels and also caused an embankment of the Forbay Lake reservoir to fail, sparking a flash flood in the park. The Minnesota Department of Natural Resources said Tuesday that the park will remain closed indefinitely, and all camping and lodging reservations have been canceled through the end of October.

The flooding mangled the park's Swinging Bridge, severing the only in-park link between miles of trails on either side of the St. Louis River. While the bridge's columns still stand, the span is wrecked -- and figuring out how to fix the bridge, built in the 1930s by the Civilian Conservation Corps, is a priority.

"It's a historic bridge and we have to go through the State Historic Preservation Office to redesign the permanent structure when we do rebuild it, but there's a lot of questions around that," said Courtland Nelson,

Minnesota DNR director of parks and trails. "Anything that was built in the 1930s, we don't have the materials on hand, we don't have the craftsmen. We'll have to do a lot of evaluation. ... First and foremost for us with regards to this bridge is do we do something temporary ... or do we want to seek some kind of permanent fix" right away.

Park manager Gary Hoeft said initial surveys of trail damage -- including areas south of the river -- were scheduled to be finished Tuesday. He said at least 20 other bridge structures in the park were wrecked. Flooding also cut off the park's water and sewer service.

"We've got a lot of culvert areas that have been washed out ... a lot of slumping, landslides from higher up on the hills that have slid down onto the trails," Hoeft said. "We found some sinkholes -- and a few of them don't appear to have bottoms."

The DNR said full refunds will be issued to people who had camping and lodging reservations at the park through Oct. 31. As a result, the agency expects to lose about $175,000 in revenue. In 2010, Jay Cooke State Park hosted more than 302,000 visitors, nearly 35,000 of whom stayed overnight in the park.

Highway 210

Duane Hill, district engineer for the Minnesota Department of Transportation in Duluth, said flooding caused an estimated $35 million to $40 million in damage just to the 8.2-mile corridor of Highway 210 through the park, with four major washouts isolating the park and Minnesota Power facilities.

"We have a multidisciplinary team doing assessments on the four washouts that we have on this roadway, and we're going to be putting together a series of alternatives for rebuilding the road at those locations," he said. "Alternatives are going to range from culverts to bridges, and we're going to be looking at innovative methods to speed up the construction."

Those alternatives could include, at least temporarily, spanning the washouts with Bailey bridges -- a pre-fab bridge that can be set up quickly, often used for military purposes. Hill said MnDOT also is looking at new kinds of bridge abutments and structures that balance cost-effectiveness, durability and speed of construction.

Hill said crews have opened a one-lane road to Minnesota Power's lower dam near Fond du Lac, and estimated that access to the park and other power facilities should be in place by early fall. Reopening of the full corridor -- including bridging the massive gap east of park headquarters caused when the embankment of Forbay Lake gave way -- may take at least a year.

Until then, Hill warned people against unauthorized ventures into the park, noting that parts of the highway are continuing to slump and give way two weeks after the flood.

"We really want the public to know they shouldn't be here; there's imminent failures on the slopes on the roadway," he said. "Please obey the road closed signs. ... Just be patient and we'll get this corridor back open to the public."