Dalton Bridge still on track for 2023, with steeper price

During the Oct. 1 Lincoln Government Day meeting, Lewis and Clark County Road Manager Kevin Horne said County Engineer Dan Karlin and Bridge Manager Clay Caudle met with Montana Department of Transportation engineers recently for an alignment grade review for the new Dalton Mountain Road Bridge to ensure the elevations and alignment will work with the new structure.

Horne said they still expect to see construction of the new bridge during three-month period in 2023. He said the new structure will be a 150-foot, single span, pony-truss bridge, which will use piers on the bridge ends, but won't use abutments in the river.

Horne said the plans call for a different method for placing the piers.

"Usually with a bridge of that magnitude, they'll drive iron in the ground. For days and days, you'll hear 'ding, ding, ding, ding' just nonstop," Horne said. "This design, they elected to go with drilling them with big augers,48-inch augers. That will be a lot better for them to secure permitting through Fish, Wildlife and Parks, because fisheries are a concern when you start making those pinging noises."

The new bridge is projected to cost about $3.48 million dollars, which is a notable increase from 2018. Before being accepted into MDT project under the Off-System Bridge Program the county expected to spend about $1.1 million for a two-span bridge, or $1.25 million for single span. A Treasure State Endowment Program Grant award approved by the 2019 state legislature provided the county with $558,000 for the project, which was used as matching funds when it became an MDT project.

With limited room in the county's right of way, a temporary bridge won't be used during construction of the new bridge. Instead, residents in the Willow Creek and Dalton Mountain area will have to detour around Herrin Lakes Road.

"We'll have to come up with some planning," Horne said. "Herrin Lakes is the only way out, so we'll probably have to upgrade our maintenance during that 90-day cycle.