The 92-mile road through Denali National Park and Preserve will remain closed near the halfway point for another three years due to newly discovered construction delays in the area of a treacherous landslide.
Park officials closed the Denali Park Road west of the Pretty Rocks Landslide in August 2021, saying it was no longer feasible to safely maintain. The road provides the only vehicular access into the 6-million-acre park. Buses carrying visitors into the park now turn around at Mile 43.
Road construction initially expected to wrap up in 2025 is now not expected to be complete until 2026. Park officials say the delay stems from a combination of a long winter that delayed the start of construction and the discovery that crews will need to extract more than two times as much clay as originally expected from the Pretty Rocks area.
The road has now shifted 72 feet below its original location, park spokeswoman Sharon Stiteler said on Monday.
Officials plan to build a roughly 475-foot steel truss bridge to span the landslide. A retaining wall will help stabilize the bridge and officials say they will use other techniques to reinforce the ground and mitigate any potential permafrost thaw.
The project is expected to cost roughly $100 million and will take three summers, Stiteler said. A design contract was awarded last summer and a construction contract was awarded in January.
The project is challenging for a number of reasons, including the small, remote location and the short construction seasons in the park, Stiteler said.
Excavation to prepare for bridge construction was initially planned to begin last month, but will now begin in July.
Officials learned recently that roughly 80,000 cubic yards of clay will need to be removed from the west side during excavation, rather than the previously estimated 30,000 cubic yards, Stiteler said. That discovery, paired with long-lasting winter conditions this year, caused the work to be delayed this summer and extended an additional season, she said.
The road reopens each year to private vehicles for a brief period before bus season begins and private vehicles are only able to access up to Mile 15. The opening and closing dates depend on snowfall each year.
Despite the partial road closure, Stiteler said, visitors are still coming to the park.
The park this year could exceed the more than 600,000 people who visited in 2019, she said. The park saw lower numbers of visitors during the pandemic, but reported more than 427,000 visitors last year.
“We’ve noticed that we’re seeing a lot more activity in the front country this last year,” Stiteler said. “The kennels had record attendance at some of their dog demonstrations. ... People are still going out to East Fork, which is about as far as they can go, about 43 miles, but they’re also spending way more time in the front country and exploring those trails, visiting the dogs, looking for ranger programs.”