Discover the Longest Bridge in Idaho – A 9,300-Foot Monster

Written by Ashley Day
Updated: July 30, 2023
© Amehime/
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Key Points:

  • The Long Bridge is situated in Bonner County, connecting the charming town of Sandpoint to Sagle over Lake Pend Oreille.
  • Originally built in the early 20th century, the bridge has undergone multiple reconstructions to meet the growing transportation demands of the area.
  • The bridge spans approximately two miles across the southern tip of Lake Pend Oreille, although the exact measurements may differ depending on the source.

Discover the longest bridge in Idaho. For a short time in the early 1900s, some considered it the longest bridge in the world.

The longest in Idaho was originally built as a railway bridge under the name Sandpoint Long Bridge.

Tucked away amidst the mesmerizing natural beauty of the northern Idaho panhandle, you will find a true architectural marvel. The Long Bridge was initially named the Sandpoint Long Bridge after the town it links to. This remarkable structure is not only the longest bridge in Idaho. It is also a testament to the exceptional engineering prowess that went into its creation.

Location of the Longest Bridge in Idaho

Located in Bonner County, the Long Bridge connects the scenic town of Sandpoint to Sagle over Lake Pend Oreille. It was originally constructed in the early 20th century. The bridge has been reconstructed several times to accommodate the region’s increasing transportation needs while meeting modern safety standards.

Though exact measurements vary from source to source, the bridge spans approximately two miles across the southern tip of Lake Pend Oreille. Which is the largest lake in Idaho and one of the deepest in the United States. This massive lake and its surrounding landscapes offer habitat to an astonishing array of flora and fauna. Making the Long Bridge not just a conduit for transportation but a window into Idaho’s diverse ecosystems.

The Long Bridge is an Experience

For drivers and pedestrians alike, the journey across the bridge is as captivating as the destination. It provides panoramic views of the surrounding mountains. In addition to vast expanses of water and verdant landscapes. It acts as a gateway into the enchanting world of Idaho’s wilderness. It is a vital connection between the human community and the natural ecosystems it transects. And offers a unique perspective into the complex, interconnected webs of life that characterize this part of the world.

Despite the evident human influence, this area retains its ecological integrity to a large extent. Lake Pend Oreille and its surrounding landscapes serve as a haven for a variety of wildlife species. Which include elk, deer, black bears, and a plethora of bird species. For the nature lover, the Long Bridge serves as the threshold to a world that continues to thrive in harmony with human existence. It is an embodiment of the delicate balance between human development and natural preservation.

View of Lake Pend Oreille and the town of Sandpoint, Idaho, from the top of the mountain
The Long Bridge was initially named the Sandpoint Long Bridge.


History of the Longest Bridge in Idaho

The Long Bridge is not just a bridge but a testament to the area’s rich past. It is steeped in history and stands tall in the mesmerizing landscape of Northern Idaho. Here we delve into the fascinating history of this architectural marvel, the longest bridge in Idaho. It stands as an eloquent witness to the changing times.

The Long Bridge was originally constructed in 1908 as a railway bridge by the Northern Pacific Railway Company. Specifically during a period of rapid expansion in the region. At the time, Northern Idaho was buzzing with the prospect of new opportunities. Particularly in the timber and mining industries, creating a pressing need for improved transportation infrastructure.

The Long Bridge was a strategic response to this need. Its location at the mouth of the Pend Oreille River was deliberate. The main purpose was to facilitate the transport of goods and people across the largest lake in Idaho. The bridge’s construction was a game-changer for the region’s burgeoning industries. And it provided an efficient and reliable transportation link that played a crucial role in fueling the region’s economic growth.

How Did the Longest Bridge in Idaho Get Its Name?

Its initial name, “the Sandpoint Long Bridge,” originates from the town it connects to on the northern end; Sandpoint, ID. This bustling town is a hub of commerce and culture in Bonner County. A trait the bridge helped foster by enhancing its connectivity.

However, as the decades rolled on, the bridge faced the challenges of time and wear. Recognizing the increasing demands of modern transportation, the Idaho Transportation Department undertook the project of reconstructing the bridge in the mid-20th century. The new and improved Long Bridge opened to the public in 1956. It featured a more robust design and increased load-bearing capacity to accommodate heavier traffic. This upgrade marked a new chapter in the bridge’s history, one defined by resilience and adaptability.

Yet, the story of the Long Bridge did not stop there. In the late 1980s, plans were made to reconstruct the bridge again. This time to meet evolving safety standards and increasing traffic demands. The new structure opened in 1981. It was a 2-mile long, two-lane highway bridge that retained the original’s historic charm while providing safer and more efficient passage.

The Pedestrian Long Bridge

There is more to add to the bridge’s historical significance. The original decommissioned railway bridge was repurposed into a pedestrian bridge known as the “Pedestrian Long Bridge.” This provided a serene walkway with stunning views of Lake Pend Oreille and the surrounding mountains. It has since become a favorite among locals and tourists for recreational activities such as biking, walking, and bird-watching.

Today, the Long Bridge is more than just a transportation link. It is a symbol of the region’s history, resilience, and commitment to progress. It stands as a silent storyteller. With its steel and concrete body narrating a century-long tale of human ingenuity, perseverance, and adaptability.

Whether you’re crossing it for the first time or the hundredth, the Long Bridge invites you to pause, take in its breathtaking views, and reflect on the fascinating history that has shaped it.

Sunset falling beautifully behind a railway bridge in Sandpoint, ID.
The Long Bridge is roughly 2 miles long.

©Block City Photography/

Long Bridge Physical Description

Standing as a proud testament to architectural prowess amidst Idaho’s picturesque scenery, the Long Bridge is an impressive sight to behold. It’s a simple yet striking example of a box girder bridge, a common design known for its strength, efficiency, and durability. This type of design involves a top and bottom deck, or “flanges,” connected by vertical support known as a “web,” creating the signature ‘box’ structure.

Stretching approximately 2 miles (or about 3.2 kilometers) across the glimmering waters of Lake Pend Oreille, the bridge provides a conduit for U.S. Route 95, a major north-south highway. A testament to the engineering marvel, it possesses dual lanes catering to a steady stream of vehicles that traverse the stretch, demonstrating aesthetic elegance, exceptional functionality, and resilience.

The Design of the Longest Bridge in Idaho

Characterized by its sturdy, vertical pillars, the bridge’s structure is constructed of robust steel and concrete. These evenly spaced pillars descend majestically into the tranquil lake waters, creating an intriguing pattern of repetition and symmetry. The bridge’s steel superstructure is partially visible, displaying a rhythmic series of interconnecting cross beams that lend an industrial charm to the structure.

Complementing the main vehicular bridge, the Pedestrian Long Bridge, the old railway bridge repurposed into a footpath, runs parallel. This structure presents a serene pathway, echoing the rugged charm of the main bridge while offering sweeping, uninterrupted views of Idaho’s natural splendor.

The Long Bridge, with its functional design, sturdy construction, and harmonious integration with the surrounding landscape, stands as a symbol of the delicate balance between human engineering and nature. It’s a celebration of the resilience of the human spirit, the drive for connectivity, and a deep respect for the environment it inhabits.

View of Lake Pend Oreille and the mountains of Sandpoint North Idaho, USA, from the Sandpoint Bay Long Bridge on a beautiful summer afternoon
The Long Bridge is an example of a box girder bridge.

©Kirk Fisher/

Problems With the Longest Bridge in Idaho Over the Years

Just as the construction of any architectural marvel involves a series of challenges and triumphs, so too does the story of the Long Bridge in Sandpoint, ID, reflect the dance between adversity and achievement. And deeply intertwined are these challenges with its history.

In the Early-1900s

The original Long Bridge, built by the Northern Pacific Railway Company in 1908, was a product of its time. While it served as an essential link for the burgeoning timber and mining industries in Northern Idaho, it wasn’t without its challenges. The bridge was constructed mainly from heavy timber and steel, with concrete piers providing support. It was subject to the ravages of time and the elements. Harsh winters and the constant wear and tear from the heavy, continuous use gradually took a toll on the bridge, compromising its structural integrity over time. Additionally, being a single-track railway bridge, its capacity was limited and unable to cater to the region’s growing transportation needs.

In the Mid-1900s

By the mid-20th century, the shifting transportation landscape had introduced new demands. The original railway bridge was not designed to handle the heavy vehicular traffic that the region was experiencing. Recognizing this, the Idaho Transportation Department initiated a project to reconstruct the Long Bridge, leading to the unveiling of the new Long Bridge in 1956. This new structure was a highway bridge designed to cater to increasing traffic. However, the new design had its own set of challenges.

Though designed to withstand a greater volume and variety of traffic, it soon became clear that the newly constructed bridge still needed to be more to keep up with the region’s rapid growth. Traffic congestion became a recurrent issue as the two-lane bridge struggled to accommodate the ever-increasing number of vehicles. Safety concerns were also a problem as the bridge’s design and structure began to show signs of wear.

In the Late-1900s

These issues led to another wave of construction in the late 1980s. The newly renovated bridge unveiled in 1981, was designed to meet evolving safety standards and growing traffic demands. It was a two-mile-long, two-lane highway bridge that retained the original’s historic charm while providing safer and more efficient passage.

Present Day

However, even after these renovations, the Long Bridge faced challenges. The bridge’s narrow design, while aesthetically pleasing, posed practical issues. Inclement weather, particularly in winter, continues to pose threats to the bridge’s safety and function. Snow and ice can make the bridge slippery and challenging to navigate, leading to potential safety concerns.

Furthermore, the bridge’s limited capacity continues to be a challenge. Despite the renovations, the Long Bridge, with its two-lane structure, still faces occasional traffic congestion, particularly during peak travel times. Future renovations or extensions may be required to address this ongoing issue.

While the Long Bridge is an architectural marvel and a testament to human ingenuity, it is not without its challenges. The bridge has faced and overcome numerous obstacles, from its initial construction to various renovations. However, just like the resilient spirit of Idaho itself, the Long Bridge continues to serve its function, connecting people and places.

Sandpoint Idaho USA Pano Drone View Lake Pend Oreille Snowy Winter Sunset Cityscape
The Long Bridge can be challenging to drive during the winter months when there is ice and snow.

©Cascade Creatives/

Wildlife Found Around the Longest Bridge in Idaho

Nestled amidst the sweeping panoramas of Idaho’s landscape, the Long Bridge of Sandpoint is more than a passage; it’s a window into a rich ecosystem teeming with diverse wildlife. Over, under, and around this architectural marvel, an array of animals calls this region home.

Aquatic Life

Under the Long Bridge, the waters of Lake Pend Oreille support a thriving aquatic community. The lake is known for its abundant fish species, a veritable paradise for anglers. Kamloops Rainbow Trout, Lake Trout, Bull Trout, and Cutthroat Trout swim in these waters, creating a vibrant, splashing tapestry of life beneath the surface. The lake’s depth and size make it an ideal habitat for these species, allowing them to thrive in its cool, clean waters.

Perhaps one of the most fascinating creatures in Lake Pend Oreille is the White Sturgeon, North America’s largest freshwater fish. These aquatic giants, which can grow up to 20 feet long and live for over a century, are an incredible sight if you’re lucky enough to spot one.

Lake Pend Oreille is also home to an array of smaller creatures that form the foundation of the food chain. These include aquatic insects, crustaceans, and mollusks, all contributing to the lake’s rich biodiversity.

Aerial Animals

Moreover, above the water, the air is alive with the flutter and call of numerous bird species. The marshes and riparian habitats around the lake are a haven for waterfowl and migratory birds. From the melodious songs of warblers and sparrows to the commanding presence of eagles and ospreys, the area presents a symphony of avian life. One might catch a glimpse of a Great Blue Heron gracefully stalking its prey in the shallows or a Bald Eagle soaring overhead, casting a majestic silhouette against the Idaho sky.

Land Animals

Beyond the banks of Lake Pend Oreille, the surrounding landscapes offer a variety of habitats supporting a rich array of wildlife. The dense forests are home to mammals such as deer, elk, and moose, which can often be spotted grazing in meadows or ambling through the undergrowth. Smaller creatures, like the Red Squirrel and Snowshoe Hare, add their quiet charm to the woodland tapestry.

Among the predators in the area, one might find the elusive Cougar, the Bobcat, and the Black Bear. These creatures, while more rarely seen, play a crucial role in maintaining the balance of the ecosystem.

In addition, the region is a habitat for a variety of reptiles and amphibians. From the Western Painted Turtle basking on a log to the Pacific Tree Frog’s chorus filling the night air, these creatures add another layer of richness to the local biodiversity.

Furthermore, if you find yourself crossing the Long Bridge, please take a moment to appreciate the wealth of life that it overlooks. From the shimmering scales of fish in the depths of Lake Pend Oreille to the majestic flight of an eagle in the sky, the bridge is not just a crossing; it’s a window into the vibrant heart of Idaho’s wildlife.

After the swoop, an eagle catches a fish and takes off leaving a trail of splashing water.
Bald Eagles are a common sight over Lake Pend Oreille.t

©Gregory Johnston/


The Sandpoint Long Bridge in Idaho is an emblem of the region’s history and natural beauty. It serves a purpose as a significant transportation route. And it stands as a testament to the region’s remarkable wildlife and rich ecosystems. Its presence also underscores the powerful narrative of human ingenuity and resilience. As well as our continuous adaptability to the evolving demands of time and space.

Moreover, the Long Bridge was initially constructed in roughly 1908. It has had a tremendous journey from a railway bridge to its current form as a highway bridge. This bridge is intertwined with the region’s economic and social evolution. Despite the challenges faced over the decades, the Long Bridge continues to serve its community. Faithfully connecting places, people, industries, and histories.

Furthermore, underneath the bridge, the waters of Lake Pend Oreille are a flurry of aquatic life. You can find the mighty White Sturgeon, North America’s largest freshwater fish. In addition to various trout species, the lake’s waters provide a vibrant aquatic habitat. Above the water, the air teems with a wide variety of bird species. At the same time, the surrounding landscapes support an array of mammals. Including graceful deer and moose to elusive predators like cougars and black bears.

Despite the inevitable challenges associated with a structure of its age and importance, the Long Bridge stands as a shining symbol of Idaho’s vibrant history and natural beauty. It serves as a reminder of the balance that can exist between the constructs of man and the bounty of nature.

The Featured Image

View of Lake Pend Oreille and the town of Sandpoint, Idaho, from the top of the mountain
© Amehime/

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About the Author

Ashley is a freelance writer and wildlife photographer. Insatiably curious and drawn to knowledge, she has a passion for conservation and sharing the wonder of the natural world with others.

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