More Great Content:

The Highest Bridge in Montana Will Make Your Stomach Drop

Written by Thomas Godwin
Updated: August 2, 2023
© Laurens Hoddenbagh/
Share this post on:


Key Points

  • Koocanusa Bridge is the highest bridge in Montana.
  • Koocansa Bridge is 270 feet high and 2,437 feet long.
  • The bridge was constructed in 1972.

The highest bridge in Montana—which also happens to be the longest bridge in Montana—is the Koocanusa Bridge. The bridge is 270 feet high (though that can change as the levels of the lake below rise and fall) and 2,437 feet in length, just shy of half a mile.

Alone, a bridge is a remarkable feat of human engineering. It’s a concrete and steel umbilical cord, connecting two points on maps since ancient times. Bridges bring together two land masses and have connected cultures and nations in many ways over the centuries. The highest bridges, however, are always the most fun.

The highest bridge in Montana itself wouldn’t be there today if not for the construction of the Libby Dam. Koocanusa Lake is a reservoir, formed from the structure of the Libby Dam, and connecting Highway 37 to a small Mennonite community and the town of Yaak.

History of the Koocanusa Bridge

In the mid-1960s, the Army Corps of Engineers arrived on the scene, with the goal of constructing a dam.

The construction of the Koocanusa Bridge begins with Libby Dam. In the mid-1960s, the Army Corps of Engineers arrived on the scene, with the goal of constructing a dam. At the time, all that existed was the third largest contributor to the Columbia River, the Kootenai River, and the surrounding countryside.

The goal of most dams is to harness the power of water, converting it into a form of clean energy for homes and businesses to grow around. That was the case with the inception of the Libby Dam, except Libby Dam also has a second, ulterior motive—reducing the potential for disastrous flooding in the region.

The dam’s construction was one of many collaborations between the United States government and the government of Canada. Montana was a secondary bystander in the construction of the eventual 422-foot dam, 17 miles north of the town of Libby.

However, Montana and the local towns within the Libby Dam’s purview benefit immensely from the Dam’s power-harnessing capabilities. Libby Dam was completed in 1972 and stands today as a testament to an immense level of engineering prowess. But, actions have consequences, and the natural consequence of this damn, is the highest bridge in Montana.

Building the Koocanusa Bridge

Whether you’re an architect, appreciate a good-looking bridge, or don’t really know one way or the other, you can’t help but be impressed with the Koocanusa Bridge. It’s not the highest bridge in the world and certainly not the longest. However, it’s unique and strangely beautiful in its own, secret way.

“Secret” because there’s nothing much out there. The world is quiet along this stretch of the Koocanusa River. The bridge is often the only sound source, besides the wind and the creaks and groans of shifting steel and concrete. The only thing in this part of the world is a handful of ranches and a quiet, industrious Mennonite community.

The bridge is a goliath of architectural achievement—the monster latched down with giant, steel cables, each one secured to the bedrock of the earth on the eastern and western shorelines. The Koocanusa Bridge stretches over the emerald green waters of the Koocanusa Lake, itself a still and quiet body of water, with the occasional goosebumps, rifled up by a passing wind, boat, or kayak.

Construction on the highest bridge in Montana reached completion in 1972, forging a thin tendril between opposing sides of the lake. If not for the bridge, the town of Yaak, Montana would have been cut off from the shopping districts, schools, businesses, and the social and economic benefits of the other side.

The multi-truss bridge, a Morrison-Maierle, Inc design, is a part of the Kootenai National Forest and maintains the invaluable artery between the logging industry and access to timber. The bridge, and those who had a hand in its creation, are recipients of the American Institute of Steel Construction award for the most beautiful bridge in the country.

The highest bridge in Montana itself wouldn’t be there today if not for the construction of the Libby Dam.

Where is the Koocanusa Bridge Located on a Map?

The Koocanusa Bridge is a popular landmark located in Montana, USA. If you are looking to visit the bridge and want directions, it can be found along US Route 93 between Eureka and Whitefish. The bridge spans Lake Koocanusa, which was created by the construction of Libby Dam on the Kootenai River. The area around the bridge offers stunning views of the surrounding mountains and outdoor activities such as fishing, hiking, camping, and boating. So if you’re planning a trip to Montana or simply passing through, be sure to add a stop at Koocanusa Bridge for an unforgettable experience!

Life Beneath the Highest Bridge in Montana

Animals in Montana
Trout is the primary fish swimming around in the 29,000 acres Lake Koocanusa covers, prime feeding for bears.

©Islandwave Photography/

As quiet and peaceful as the area is, with only the occasional vehicle crossing the bridge, Lake Koocanusa is a quiet and peaceful area. Few, if any, disturbances ever visit the lake. While it may seem that way, standing from one of the two, elevated sidewalks on the bridge, there is much going on beneath, both in the water and out.

Trout is the primary fish swimming around in the 29,000 acres Lake Koocanusa covers—rainbow, bull, cutthroat, and brook trout mostly. Kookanusa Lake is also home to a sizeable whitefish population, along with Kokanee salmon, bass, pike, and yellow perch.

Ten years ago, the aquatic life of Kookanusa Lake faced extinction and it had nothing to do with the highest bridge in Montana. Water testing revealed absurdly high amounts of selenium in the lake, prompting an investigation and a subsequent discovery that the local coal mining operation was leaking selenium into the river via the Elk River.

Selenium makes it difficult if not impossible for fish to reproduce. A rapid dying off of the fish in the Kookanusa River would have dire consequences for the beavers, elk, and deer. Kookanusa is a highly important winter range for the latter two. The badgers, long-billed curlews, and turtles would find themselves in a pickle as well.

Fortunately, thanks to quick action ten years ago, the selenium levels in Lake Kookanusa are nominal again, and the local wildlife has every opportunity to thrive.

Final Thoughts on the Highest Bridge in Montana

The Kookanusa Bridge may be the highest bridge in Montana and the longest as well, but it certainly isn’t breaking any bridge records on a national scale. The Kookanusa Bridge is the direct result of necessity and consequence. Once Libby Dam went up, the bridge became a must, just to keep life on either end of the lake connected.

Montana is a huge state, the fourth largest in the country, and it’s still mostly rural, with farmlands and ranches making up most of the human occupation across the vast acreage of the state. The Kookanusa Bridge is a modern instrument in an ancient environment. A lone sign that humankind was once here and built this multi-truss giant in a sea of wilderness.

The Featured Image

Lake Koocanusa Bridge
Lake Koocanusa Bridge won an award for its beauty.
© Laurens Hoddenbagh/

Share this post on:
About the Author

Thomas is a freelance writer with an affinity for the great outdoors and Doberman Pinschers. When he's not sitting behind the computer, pounding out stories on black bears and reindeer, he's spending time with his family, two Dobermans (Ares and Athena), and a Ragdoll cat named Heimdal. He also tends his Appleyard Ducks and a variety of overly curious and occasionally vexatious chickens.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.