Plans to renovate Bloomington's Old Cedar Avenue Bridge are also spurring an effort to make part of the adjoining wildlife refuge more parklike and accessible to more users.

At an open house this week about the $12.7 million bridge renovation, mock-ups of the area where the bridge links to the Minnesota Valley National Wildlife Refuge showed more than the simple trail sign and parking lot that exist now. There were restrooms, a drinking fountain, a new parking lot with space for buses and improved trails that could accommodate people in wheelchairs. A picnic shelter and a "grassy amphitheater" for classes sit near the bridge.

A small floating dock that serves bird-watchers would be replaced with a bigger, longer dock that could accommodate groups of people.

Bloomington is working in concert with the U.S. Fish and Wildlife Service, which runs the refuge, on plans for the area.

Shelly Pederson, Bloomington city engineer, said the area needs an upgrade as a place where major trails will meet. She said she is "very excited" about the bridge renovation and other improvements.

"I think it will be a great amenity for Bloomington and the region, because [the bridge] will cross over south of the river into other communities," she said. "This will be used for recreation and by commuters."

Refuge manager Tim Bodeen said the plans for the area near the bridge are part of a bigger Fish and Wildlife Service effort to reach out to urban residents. The refuge, which stretches 70 miles along the Minnesota River to Henderson in Sibley County, is one of a handful of urban refuges in the country. The headquarters sit a short distance from the Mall of America.

"We're trying to make this a more interactive site, with better trails and handicapped access, a small picnic area," Bodeen said. "We'd have a better floating dock. We're trying to make that node down there feel more parklike, to attract an urban audience."

Fish and Wildlife officials have been concerned that as people increasingly live in cities and suburbs, they lose touch with nature. Bodeen said the nationwide urban initiative, which is just beginning, is centered at Minnesota Valley and refuges near Detroit and St. Louis.

While Bodeen said he wants the entry area to the bridge to be a showcase for the refuge, he said the wild nature of the rest of the refuge will remain intact.

About the bridge

But the star of the open house in Bloomington was the bridge. Built in 1921, the camelback steel truss structure is on the National Register of Historic Places.

Once a major connection across Long Meadow Lake to a swinging bridge that crossed the river, the Old Cedar Avenue Bridge closed to vehicle traffic in 1993 and to bikers and pedestrians in 2002. Bloomington has owned it since 1981, when the state gave it to the city.

When it reopens, it will connect to a pedestrian and bike bridge that hangs from the side of the Hwy. 77 bridge, joining biking trails in Hennepin and Dakota counties. The planned Minnesota Valley State Trail would run near the bridge.

While a generation of refuge users and bikers know the bridge as a spidery black structure with a deck of rotted timbers and a lot of rust, SRF Consulting Group drawings of the renovated bridge show it painted in its original dark gray with a new concrete deck for walkers and bikers.

An in-depth inspection this winter revealed that while bridge parts that are near or under the water are rotting, the steel arches and other upper sections are in fairly good condition.

"Anything below the deck is in poor shape and almost all of it needs to be replaced," Pederson said. "Above the roadway, where there is less salt damage, is in really good shape."

Fixes urged … in 1923

Bloomington officials, who approved the bridge renovation in September and have $14.3 million to pay for it, long considered the rickety bridge a liability. One of the historic documents included with the engineering reports indicates they weren't the first to have issues.

A 1923 inspection report shows that though the bridge was barely two years old, some piers already listed as much as 7 inches. Expansion joints that were supposed to allow for expansion and contraction in heat and cold were closed. Unless the bridge was fixed, the report said, some trusses might buckle when summer came.

The problem apparently was too much fill on one end of the bridge. The north abutment was rebuilt that year and again in 1957, probably because bridge supports kept shifting in their boggy wetland home.

"Everything moves with freeze-thaw and wet conditions," Pederson said. "It's in harsh conditions."

The new bridge renovation will be complicated, requiring removal of lead paint, protection of the wetland and probably construction of a temporary platform or bridge for construction.

Exactly how things will work will become clearer as engineering plans advance through the summer.

"We want it to be there for the next 50 years, in good repair and easy to maintain," Pederson said.

While the construction schedule isn't yet set, the bridge is expected to reopen in spring 2016.