Bridge proposed along section of slumping Denali park road

Landslides in the area go back decades but usually required maintenance every two to three years

The National Park Service is proposing a large steel bridge along a section of the only road that runs through a sprawling park in Alaska — a stretch that officials say has been rapidly slumping amid changes in the climate.

About half the mostly gravel road that runs through Denali National Park and Preserve — home to North America’s tallest peak — has been closed to buses and other recreational traffic since late August, and such traffic will remain restricted to mile 43 again this year. Without a bridge, that section would remain closed indefinitely, the agency said.

The park service released an environmental review Thursday that outlines two phases of proposed work. The first would include construction of a 400-foot bridge spanning the Pretty Rocks landslide area, retaining walls and a “slight road alignment” on the west side of the bridge.

The first phase is expected to last about two years, and road access through the Polychrome Pass area is not anticipated during that time, according to the report.

The overall plan also proposes other measures within a 2-mile stretch of road “to ensure that access through the Polychrome area wouldn’t be subsequently jeopardized by another nearby hazard,” the report states.

The park service is taking comments on the review through Feb. 13.

Landslides in the area go back decades but usually required maintenance every two to three years, the park has said. Conditions have deteriorated, however, in recent years. Last summer, crews had to spread “up to 100 truckloads of gravel per week to fill in the slumping road” and couldn’t keep up with “the increasing displacement and road surface instabilities,” according to information provided online by the park.

The park in August said climate change, “with its associated warmer winter temperatures and increased precipitation, has taken what was previously a problem solved by maintenance staff performing road repairs and made a challenge too difficult to overcome with short-term solutions.”

The Interior Department announced Thursday that $25 million in federal infrastructure funds would go toward the project. The department said the money would allow for phased work to begin this year.

The park is ready for visitors despite the partial road closure, its acting superintendent, Brooke Merrell, said in a statement.

“During construction, visitors will continue to have access to great wildlife viewing, views of Denali, front-country trails and backcountry hiking and camping,” Merrell said.

Denali National Park and Preserve covers 6 million acres. It received more than 600,000 visitors in 2019, the year before the pandemic.