New swinging bridge to be wider, lower and still swinging

The replacement for the beloved suspension footbridge west of Kootenai Falls will still have the familiar swing, officials said at a recent public meeting, as well as various upgrades with safety, cost and character in mind.

Held Aug. 15 at the Silver Spur in Troy, the meeting was intended as part of the initial scoping for the replacement project, a period which will last until the fall.

Ranger Kirsten Kaiser began the meeting by saying “regarding the swinging bridge replacement: we’ve known about it for about a year and it is not optional. This is a safety issue.”

After a 2015 routine bridge inspection, required every five years by law, the inspector said the bridge was safe for now, but would need a replacement plan to bring it up to safety codes. Construction could begin as soon as next summer.

The plan could have been to replace parts of the existing bridge, but replacing the entire bridge would cost about the same and eliminate certain unknown factors, such as the integrity of underground cables, Kaiser said.

The meeting was attended by all three Lincoln County Commissioners, Troy Mayor Darren Coldwell and various community representatives, including those from David Thompson Search and Rescue and the office of Senator Tester.

The iconic bridge that exists today was designed in 1950, and the cable and concrete anchors of the bridge have not been replaced since, although other parts of the bridge were replaced in 1993 and the wooden decking material has been replaced every 3 to 4 years, said Recreation Technician Dave Thorstenson.

Funding for the new bridge, estimated to cost between $400,000 and 600,000, was found through a Federal Lands and Transportation Department grant, said Recreation Program Manager Mary Laws.

“We have received $400,000 from federal lands,” Laws said. “We’ve got the funding, so we’re kind of working backwards from there.”

Getting the necessary equipment and building materials across the railway may the biggest hurdle, she said, both financially and logistically. Helicopters will need to be used, requiring consultation with Fish, Wildlife and Parks.

Kaiser said the district has been in conversation with the Kootenai-Salish and Kootenai tribe of Idaho for whom the bridge area is important.

“I am not here to speak for the tribes,” Kaiser said. “But I will say there has been some concern from them about people crossing the bridge and using the land on the other side, especially at certain times of the year.”

Other community representatives had expressed concern after the district posted July 31 on Facebook about the bridge’s replacement, Kaiser said. The main concern was about keeping the bridge’s character, its suspension design and therefore its swing.

Coldwell and Commissioner Jerry Bennett said during the meeting that the feedback they had heard matched the concerns posted to Facebook.

Jim Scoles of Morrison and Maierle, the engineering team contracted to design the new bridge, said preliminary designs include a similar ‘sag’ to the current bridge.

Noah Pyle of David Thompson Search and Rescue said at the meeting that his organization’s main concern was making the bridge wide enough to be able to fit a stretcher through.

“Right now our team has to run a line across the river to get someone across, which is one of the more time consuming and dangerous things we have to do,” Pyle said. “Our bare minimum requirements to get a stretcher through would be a bridge that was 36 inches across.”

Kaiser said the engineering team is considering expanding the width from the current 2.5 feet to 3.5 feet, which would allow tight two-way traffic as well as passage of a stretcher.

Another big change will be to the bridge’s load limit. The existing bridge is rated to hold five people at any one time.

“There will be no foreseeable load limit on the new bridge,” Kaiser said.

Scoles said the new bridge will be closer to the water than the current bridge, which was designed before the Libby Dam was constructed and after a 1948 flood destroyed the previous bridge.

“Because the dam mitigates flood concerns, we can safely lower the bridge now,” Scoles said.

The materials used in the new bridge design are also up for public discussion.

Some parts of the bridge would need to be steel for strength, and that steel could either be painted or sealed with a rust patina that would last for 75 to 100 years with no maintenance, he said.

If you have any questions or comments, call the Troy Ranger Station at 406-295-4693.