Denali builds $230m bridge over moving landslide 5 years after road was cut

In August 2021, a massive landslide in Denali National Park and Preserve severed the park's sole road, leaving access to remote areas of the Alaska wilderness cut off. Five years later, a new bridge known as the Pretty Rocks Bridge now spans the unstable terrain where the road once crossed. According to the National Park Service (NPS), the approximately $230 million project includes a 475-foot steel truss bridge built across the active landslide near Mile 45.

This bridge reconnects the eastern and western segments of the road and is engineered as a long-term solution rather than a temporary fix. The bridge's completion signifies a significant step towards restoring full access to the Denali Park Road, with bus service expected to resume in the park's 2027 visitor season. The landslide's impact was extensive, affecting destinations like the Eielson Visitor Center, Wonder Lake, Kantishna, and various residential and tourism facilities.

Due to the landslide's instability, simply repairing the road was not feasible; instead, engineers devised a plan to span the area with a bridge. The bridge, constructed from steel trusses, stands 475 feet long, 50 feet tall, and 24 feet wide, designed to traverse the active slide while avoiding direct contact with the unstable ground beneath.

The project's construction posed unique challenges, including working in steep terrain with complex geology, dealing with permafrost, and navigating a short Alaskan construction season. To overcome these obstacles, crews assembled the bridge on the stable east side of the landslide, then gradually moved it across the unstable area to its final position in August 2025.

The project also included the installation of 23 thermosiphons to maintain permafrost stability around the bridge's eastern end. Beyond the main bridge, crews worked on road approaches, retaining structures, and slope stabilization. In 2026, additional construction was completed around the bridge, and rock scaling was carried out on nearby slopes to minimize the risk of falling rocks onto the road.

The bridge's construction was declared complete by late August 2026, with final restoration and removal of equipment continuing afterward. Currently, hikers and cyclists can access the western side of the bridge and continue westward, while park buses remain confined to East Fork for the remainder of the 2026 season. Full bus service along the Denali Park Road is projected to resume in 2027, reestablishing access to the western regions of Denali that have been inaccessible since the 2021 landslide.

The Pretty Rocks Bridge signifies a transformative shift in managing Denali's unstable terrain, moving away from repeated attempts to stabilize a road over an active landslide. Funded through a mix of federal transportation, disaster supplemental, and infrastructure funds, the $230 million project marks one of the park's most challenging infrastructure undertakings and paves the way for visitors to resume exploring farther into Denali beginning in 2027.