SABULA, Iowa (AP) — Illinois transportation officials are planning to give away — for free — a half-mile-long steel truss bridge built in 1932 that spans the Mississippi River between Sabula, Iowa, and Savanna, Ill. But there are conditions for those who want to take on a slice of history.

Before the Illinois Department of Transportation can demolish the bridge and build a replacement, it is required to offer the structure to anyone who promises to maintain it forever at its new location.

The bridge must be kept "in its historical significance in perpetuity" at a location approved by the Illinois DOT, said Mark Nardini, an acting environmental studies manager with the agency, according to report in The Dubuque Telegraph Herald on Friday.

The agency will approve how the bridge is moved, Nardini said. "We would also pay moving costs up to the cost of demolishing it."

But it's not clear who will take on the bridge, which is more than 2,400 feet long, 20 feet wide and 73 feet tall at its highest point. The offer is open to "any qualifying governmental or nonprofit agency," he said.

"We don't expect a lot of takers," Nardini said, chuckling. "In the past 22 years that I've worked here, we've never offered anything this size."

The bridge must be moved within 30 days of its replacement opening, and the U.S. Coast Guard needs the giant concrete piers holding up the old bridge to be removed too.

A replacement bridge will be built 100 feet south of the existing bridge. Construction for the $70 million project is scheduled to begin in 2015.