Montana’s Highest Bridge Isn’t Where You Think It Is
If you're a person who appreciates varied bridge design, it can be a real treat to wander the highways and byways of the Treasure State.
That's because Montana, which is laced with rivers and streams, has an astonishing amount of bridges. Montana Department of Transportation tracks over 5,000 in all, which includes huge spans across the major rivers like the Missouri, Clark Fork, and Yellowstone all the way down to itty bitty bridges you might not even notice on county roads.
But one bridge puts them all in their place and is so far off in the corner of Montana that you may not ever see it unless it's the destination on a specific trip.
We're talking about the bridge over Lake Koocanusa, in a remote corner of Lincoln County. And it's not only the highest, above water, in the state but also the longest in the state.
The Koocanusa Bridge just passed its 50th birthday
The bridge was constructed by the Army Corps of Engineers in the early 1970s to fill a very specific purpose. When plans were made to build the Libby Dam on the Kootenai River it created a problem for people living on the west side of the river, basically meaning they'd be cut off from shopping and services in Eureka just 13 miles away and would've had to drive miles on Forest Service roads to reach Libby instead.
So the decision was made to build the bridge
And it was a major commitment, ending up with a span that is 270 feet above the lake (although it varies with water levels in the reservoir). But the gap is also HUGE, and engineers were forced to design a bridge that would end up also being the longest in Montana, at 2437 feet. That's by far the longest in Montana, and several times longer than other impressive bridges, like the high bridge over the Clark Fork at Cyr, east of Superior on I-90.
An award-winning design
The Koocanusa bridges are tied into the bedrock on the east and west ends, and it takes five spans to support the bridge over the crossing, which takes several minutes to drive. In 1972, the bridge won an award for "Most Beautiful Bridge" from the American Institute of Steel Construction.
No traffic jams here
Unlike busy bridges in Montana's cities, the Koocanusa Bridge is never, ever clogged with traffic. In fact, because the bridge is only used to reach the ranches and the Amish community at West Kootenai I've found it wonderfully deserted every time I've crossed it. And that's true even during the height of the summer tourist season. Occasionally you'll pass a pickup, often towing a boat. Many travelers just opt to stay along the east shore of the lake coming and going from the Tobacco Valley on MT-37. If you'd like a more scenic route, or you want to reach the wonderful wild country in the Yaak, cross the bridge and head along the paved U.S. Forest Service road along the west shore.
And spend some time at the bridge to stop and take a picture. Just make sure you have a jacket, as the wind is frequently blasting up and down the lake, especially in the spring.
KOOCANUSA BRIDGE FACTS:
-2,437 feet long
-270 above the water
-Six truss spans on five piers
-Connects MT-37 and eastern Lincoln Co to the West Kootenai