DOVER — An apparent low bidder has emerged to build a new Dover Bridge, Idaho Transportation Department officials said on Wednesday.

Sletten Construction Co. of Great Falls, Mont., bid $21.6 million to replace the bridge on U.S. Highway 2, ITD said in a news release.

Sletten’s bid came in about $15 million less than the projected cost of $36.8 million.

Three Spokane, Wash., construction firms bid between $22.2 million to $22.5 million, according to ITD bid results. A fourth company, also out of Great Falls, bid the project for $23.6 million.

The bids were opened Tuesday in Boise.

Dirt is expected to turn on the construction project in late July or early August. ITD anticipates the project will be done in 2011.

It’s the third bridge project in Bonner County Sletten has recently secured. The company replaced the Thompson Park Bridge off Highway 200 near Hope last year and is lined up to replace the Lightning Creek Bridge in Clark Fork this summer.

The new Dover Bridge, a 72-foot-wide steel span, will be located slightly to the east and north of the existing bridge. The bridge will be wide enough to accommodate two eastbound and two westbound lanes.

The project also includes a stretch of new bike path on the north side of U.S. 2.

The Dover Bridge replacement project, which had been sidelined for years due to a dearth of state highway money, is being paid for with federal economic stimulus funding.

Stimulus funding is also being used to pay for improvements to U.S. 95. New passing lanes will be constructed on Moscow Mountain and widening is planned on White Bird Hill south of Grangeville.

State officials calculate that the Dover Bridge project will generate or preserve some 400 jobs.

“I am pleased these projects are going to construction this summer and Idahoans will be put to work,” Gov. C.L. “Butch” Otter said in a statement. “Safety will be substantially improved, and one of the lowest rated bridges in the state, the Dover Bridge, will be replaced.”

The Dover Bridge was built in 1937 and has not aged gracefully. The bridge’s concrete underpinnings are crumbling and its overhead structure has been struck repeatedly by over-height trucks.

Community leaders in Dover have pressed for years to have the bridge replaced and it has gone on to become something of a poster child for the plight of the nation’s deteriorating public infrastructure.

Popular Mechanics magazine listed the bridge as one the top 10 pieces of infrastructure in dire need of repair and it is about to be featured in a History Channel program entitled “The Crumbling of America.”

The program is scheduled to premiere on the evening of Monday, June 22, according to the cable channel’s Web site. Reruns are set for Tuesday, June 23 and Sunday, June 28.