As reports from the Minnesota Department of Transportation to the Legislature go, the one covering the endowment account for the historic Stillwater Lift Bridge is pretty simple. It's just a few pages long and dutifully notes the same thing for the past five years: No money in, so no money out.

But that will be changing very soon.

In next several fiscal years, Minnesota and Wisconsin will jointly begin building an endowment fund, totaling at least $3 million, for the 83-year-old bridge. The money will be drawn from agency budgets set aside to operate and maintain the span, now crossed by 17,000 vehicles daily, after it is converted for hiking and biking once a four-lane bridge 2 miles downstream on the St. Croix River opens in 2016.

The account was opened in 2009 as part of a complex deal between the states for how the new bridge will be built and maintained. It will provide a steady source of funds to keep the Lift Bridge functioning and make sure it is properly maintained once its role changes.

"Once the bridge is removed as part of the trunk highway system, it becomes a little harder to find available funding for operation and maintenance — things like paying the lift operator's salary, for example," said Kristen Zschlomer, a historian and archaeologist who supervises MnDOT's Cultural Resources Unit. "This was a way to provide that ­funding."

Many of the details for the endowment fund, such as exactly when money will be deposited into the account, are still being worked out, said Todd Clarkowski, MnDOT's St. Croix Crossing project coordinator. It's likely the amount will end up being more than the $3 million ­minimum set in the agreement.

The Lift Bridge has undergone several recent improvements, including a 2012 rehabilitation, and costs for changing it from a traffic bridge are part of the new bridge construction budget. "It will be in good shape by the time that conversion is ­complete," Clarkowski said.

Part of Stillwater's character

The Lift Bridge, so woven into Stillwater's identity (an image of the bridge is emblazoned on city police cars), is one of about 200 bridges MnDOT has identified as historically significant and worth preserving, Zschlomer said. It's an exclusive club, considering there are about 19,000 bridges in Minnesota. The list includes the Stone Arch Bridge in Minneapolis, the Mendota Bridge and the Sorlie Memorial Bridge in East Grand Forks.

Like those spans, the Lift Bridge is listed on the National Register of Historic Places. Its main significance is the way it was designed and engineered, Zschlomer said. It is one of two surviving pre-World War II vertical-lift bridges in Minnesota and Wisconsin — the other being ­Duluth's Aerial Lift Bridge. Only six were built in the two states between 1913 and 1931.

Lift operations will continue when hikers and bicyclists begin using the nearly 5-mile-long Loop Trail that is part of the new bridge project. The trail winds around both sides of the river, and will include viewing platforms 150 feet above the river that will provide panoramic views of the river valley.

The new bridge is scheduled to open to traffic in fall 2016. The loop trail and Lift Bridge conversion to a bicycle and pedestrian bridge will be completed in 2017.

Sometimes in the yearslong debate involving the new bridge, the Lift Bridge's fate was in doubt. The National Park Service, which has jurisdiction over the St. Croix, called for the removal of the Lift Bridge as a condition of approving the new ­project.

"Originally, that was a disappointment — the Lift Bridge got overlooked in that discussion," said Jeff Johnson, longtime member of Stillwater's Heritage Preservation Commission. "But now things have kind of turned around."

Members of the Heritage Commission raised their voices to make sure the bridge was spared, he said.

While there is concern in Stillwater about how diverting traffic away from downtown will affect the city, he added, attracting hikers and bicyclists also represents opportunity.

Stillwater owns acreage on the Wisconsin side of the St. Croix, Johnson said, including some prime bluff-top land and a parcel that was once a swimming beach that will offer more potential once the trail is developed. The land was bequeathed to the city by former lumber barons who helped shape the town, with covenants that protect the land from residential development.

"The Lift Bridge, for Stillwater, is very much an icon. Organizations use the image in their letterheads — it's our centerpiece," Johnson said. "I think it's just great that it's going to remain a focal point."

Jim Anderson • 651-925-5039 Twitter: @StribJAnderson