Dalton Mtn. Road Bridge TSEP contract approval recommended; county plans maintenance work

In a memo to the Board of County Commissioners, Lewis and Clark County staff recommended they approve a contract with the Treasure State Endowment Program to provide $558,806 in funding to Lewis and Clark County for the Dalton Mountain Road Bridge Replacement.

The project was accepted into the Montana Department of Transportation off-system bridge program earlier this year and is currently projected to cost $2.387 million under that program. The TSEP money will provide a portion of the funding, with MDT chipping in the $1.828 million balance.

According to the memo, the new bridge will be a two-span, 150-foot bridge, with a pre-stressed concrete bulb tee beam superstructure. Although the memo didn't include a timeline, an update in June noted the bridge replacement project is expected to happen in 2022.

Due to the extended time frame for the replacement, the Lewis and Clark County Road and Bridge Operations Superintendent Kevin Horne, told the Upper Blackfoot Valley Community Council that county crews will be conducting proactive, preventative maintenance on the bridge substructure in early October. He said part of that may include wrapping some of the piles to help prolong the longevity of the bridge until MDT can replace it.

"If you see guys working on it, it's not because the bridge is failing or anything of that nature. We're just trying to be a little bit proactive," he said.

Drivers using the bridge shouldn't see any delays or disruption as a result of the maintenance work.

Horne said the bridge was a "maintenance nightmare" last year, because the gravel they used to fill the potholes on the ends of the bridge keept disappearing. He's not sure if it's sinking or just getting "beat out" by vehicles traveling the road. He said they put additional magnesium

Dalton Mountain bridge has been open to just one lane of traffic since Sept. 14, 2017. The bridge had been closed for about a month after an MDT inspection showed nine of the bridge's 30 timber piles were compromised. TSEP awarded the grant for the bridge replacement project in 2019. initial estimates for the bridge replacement by the county were about. $1.2 million.