WINONA — State transportation and wildlife officials in Minnesota and Wisconsin are working to relocate thousands of threatened bats that have been living under a Mississippi River bridge that’s due to be torn down.

Wildlife biologists from both states estimate there are about 3,000 bats living under the Interstate 90 bridge. Wisconsin Department of Natural Resources conservation biologist Heather Kaarakka said the bridge bat colony is one of the largest known in the state. The 48-year-old bridge is being torn down as part of a three-year, $187 million replacement project.

The Minnesota Department of Transportation recently installed “bat condos” along the bridge for relocating the colony. The 4-foot-square wooden houses on stilts should provide room for up to 4,000 bats.

“I hope they think the condo is better habitat,” Kaarakka said. “It’s a build-it-and-hope-they-will-come situation.”

It’s not yet known if the bats will like their new habitat because they are hibernating. Kaarakka said it could take several years to reach full occupancy.

Wisconsin’s bat population is threatened by white nose syndrome, which has killed about 6 million bats nationwide since it was discovered in 2006, according to studies by the U.S. Fish and Wildlife Service. The disease was detected last year in a Grant County, Wisconsin, colony and has since been found in eight other counties — though not in La Crosse.