The tornado that tore through north Minneapolis May 22 has left scars and open spaces that will remain for decades in the city's largest park.

More than 300 trees were uprooted or badly damaged in 760-acre Theodore Wirth Park, which borders Golden Valley. They include giant cottonwoods, majestic elms and a heritage oak more than 300 years old.

For Andrea Weber, a landscape architect with the Minneapolis Park and Recreation Board, the destruction was especially devastating. She manages several recreation projects around Wirth Lake that have been damaged or put on hold.

Weber said crews had just finished building a 280-foot boardwalk that allowed people to walk from Wirth beach onto the lake and around the periphery of the swimming area. It was scheduled to open as soon as workers could pave a new parking area.

Now the boardwalk is gone, reduced to fragments and blown across the lake.

"It's trashed," said Weber. "It's disheartening to see things you just built get destroyed before people have even had a chance to use them."

Across the lake, a $1.7 million project to build a loop trail around the lake also has been stopped in its tracks. Crews building a boardwalk there had two pontoons wrecked, and tools are now at the bottom of the lake.

Weber said the damage probably exceeds $280,000, not including the cost to remove trees that are blocking trails.

The city is reviewing whether insurance will pay for any of the damage, she said, and hopes that disaster assistance may help pay for tree removal.

Golf is limited

The storm also blew down about 50 trees at Wirth Park's 18-hole golf course.

The front nine holes were closed for four days after the storm, and the back nine was open only to walking golfers, because the soil was too wet for golf carts.

After clearing the fairways, greens and tee boxes of trees and branches, the full course was back in play Friday. Officials said the lost revenue from the closings totaled $40,000.

Downed trees also blocked the road entrance to the historic Eloise Butler wildflower garden and damaged a fence. Volunteers repaired the fence temporarily to keep deer and other wildlife from feeding on the plants.

The garden itself, in a bowl-shaped area, was not badly damaged, park officials said.

Ralph Sievert, director of forestry, said that crews cleared trees from Glenwood Avenue and Theodore Wirth Parkway shortly after the tornado. Other than that, he said, the forestry department's 84 workers have been focused on neighborhood cleanup that will continue this week.

Clearing most park property will need to wait until June 10 or later, he said.

"It's just endless clearing and trucking, clearing and trucking," Sievert said.

City drivers are hauling about 400 truckloads of wood waste per day to the former Scherer Brothers lumberyard owned by the park board. A private firm is chipping the wood waste to use as landscape mulch, he said.

"After everything's cleared, then we have to go back and look at the trees that are still standing," Sievert said. Many that didn't fall had their "root plate" partially broken or dislodged, he said, and will need to be removed because they will never be stable and could blow down on a windy day.

He estimated that as many as 5,000 trees may have been downed or seriously damaged, including more than 2,000 on boulevards and in parks that the park board is responsible for clearing.

"We're looking at this as a summer-long project," Sievert said.

People will notice the difference with the trees gone, he said.

"It's going to be really barren," he said. "It's not going to look anything like it did before."

Heritage oak

One survivor of the storm appears to be the Rockwood oak, an estimated 314-year-old tree on the western edge of Wirth Lake. Park Superintendent Theodore Wirth named the tree about a century ago in honor of a park board attorney who urged Wirth to acquire the land.

The tornado ripped two large branches off one side of the tree, but Sievert said it appears to be stable. It has been posted with a sign to ensure that it's not cut down inadvertently.

If there's a silver lining to the storm damage, it's that the park board now has a "blank slate" to think more broadly about the park, said John Munger, executive director of the City of Lakes Nordic Ski Foundation.

"There's a tendency to not consider any new idea if any trees have to go," Munger said. "At this point [park board staff] can think about some new ideas without having to feel the guilt of cutting trees down."

That may include a more aggressive campaign to reduce invasive buckthorn and other plants in the park, he said, that are growing out of control in the spaces between large, mature trees.

Munger's group sponsors the City of Lakes Loppet cross-country ski race and several non-winter trail and paddling events and youth programs in Wirth Park.

Ironically, its volunteers planted 25 maple and 25 birch saplings in the park less than 24 hours before the tornado hit. The trees all survived the storm.

"It was the first time we've done a tree planting," Munger said. "Certainly after what happened the next day, it won't be the last."

Tom Meersman • 612-673-7388