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Park Access
Projects aimed at repairing bridges, making park road passable
By Amy Newman
Tutka, LLC replaced a box culvert at Mile 52.9 of the Denali Park Road. Fifteen loads of concrete panels were required to build the culvert.

Photo courtesy of John Sommer.

Tutka, LLC replaced a box culvert at Mile 52.9 of the Denali Park Road. Fifteen loads of concrete panels were required to build the culvert.

Photo courtesy of John Sommer.

Park Access
Projects aimed at repairing bridges, making park road passable
By Amy Newman

everal long-planned projects within Denali National Park were slated to begin construction this summer—until last September’s Pretty Rocks landslide literally blocked those plans and closed Denali Park Road at Mile 43.

Plans to replace the Ghiglione Bridge and perform road repairs near Polychrome Pass have been postponed. The landslide also affected bridge repair and mitigation work performed last summer at Mile 52, although a Herculean effort by Wasilla-based contractor Tutka, LLC and heavy coordination with park officials enabled the project to be completed on time.

Here are the updated plans for those postponed projects, plus a look at the impact the Pretty Rocks landslide had on Tutka’s work last summer.

Mitigation and repairs on Denali Park Road

Tutka, LLC, an environmental and heavy civil construction company owned by Amie and John Sommer, served as general contractor on the National Park Service’s 10(47) and 10(48) projects, which included a box culvert replacement and rockfall mitigation near Mile 52 of the Denali Park Road and minor repairs on several bridges.

“We started out with a rock scaling at the Toklat Bluffs and erosion control around the Toklat River bridge,” Sommer says of the work performed at Mile 52. “Part of that work was driving sheet pile and installing riprap around the abutment.”

At Mile 52, Tutka replaced the existing concrete box culvert over Bugstuffer Creek, adding wing walls, so “it’s a pretty good-looking pipe,” Sommer says. Tutka crews also removed lead-based paint from the Stony River and Sanctuary bridges and repainted the girders on the Stony River Bridge and the railing on the Sanctuary Bridge.

The project, which bid in May 2021 and was fast-tracked to be completed that September, faced its share of challenges even before the landslide closed the road. Sommer estimates that before the road’s official closure in September it was shut down 75 percent of the time that Tutka was working due to geotechnical drilling at Pretty Rocks. That made getting equipment and materials to and from the worksite a logistical puzzle.

“[The road] was only opened for one night a week, and you can’t haul there during the day because it’s an oversized load,” Sommer says.

Sommer says the culvert replacement alone required fifteen loads for the concrete panels, on top of the loads needed to deliver other equipment and materials. That, combined with the roughly 100 other loads that typically go in and out of the park every summer, would have meant significant delays in Tutka’s ability to complete the project on time.

To mitigate the effect of those closures, Sommer says park officials worked with Tutka to give them additional road access. Tutka, in turn, partnered with STR Alaska, which “had all the trucks we needed and were able to get everything that we needed in and out in a timely manner” when access was granted, Sommer says.

the Pretty Rocks landslide
The Pretty Rocks landslide and subsequent closure of Denali Park Road at Mile 43 interrupted several park projects scheduled to begin this summer.

Photo courtesy of the National Park Service.

An already tight deadline timeline was further accelerated when the Pretty Rocks landslide forced park officials to completely close the road in September.

“The slide started—at that point, the road was settling about a foot a day through the slide area—and [officials] shut the road down and pretty much said, ‘You guys have to be out of here by next week,’” Sommer says.

Tutka’s crew worked from dawn to dusk and park officials continued road maintenance at the landslide site to keep it passable until Tutka could complete its work and remove its equipment.

“We probably had two to three weeks of work left to do, so we had to accelerate to get everything done,” Sommer says. “But we ended up completing everything that we had to do on the contract.”

In addition to work inside the park, Tutka replaced the Rock Creek Bridge in Cantwell, which the Alaska Department of Transportation and Public Facilities had reduced to a single lane due to deterioration. Normal road closures from October 1 through mid- to late-April, combined with weight restrictions that prohibit heavy loads from being brought in until June, required construction to take place over two summers, Sommer says. He anticipates it will take an additional three weeks to place riprap along the creek edge and perform some final surfacing on the top of the road to meet the July 31, 2022 completion deadline.

Polychrome Area Improvements
Improvements to the Polychrome Area will be a permanent solution to the Pretty Rocks landslide, Federal Highway Administration, or FHWA, officials say, with work done in two phases. Phase I includes building a bridge across the landslide at Mile 45.4; Phase II includes placing a retaining wall along the road above the Bear Cave landslide at Mile 44.8. The proposed projects retain the historical character of the surrounding area and minimizes the impact on wildlife and natural resources, according to the FHWA website.

The FHWA issued an RFP, or request for proposals, to shortlisted contractors on April 28 for Phase I, with a contract expected to be awarded in August. Officials say that while some construction may begin this year, the bulk of the work will likely be scheduled to begin in spring 2023.

Ghiglione Bridge
The Pretty Rocks landslide also forced the FHWA to postpone plans to replace the Ghiglione Bridge, which traverses a drainage channel at Mile 41.9, just before the road closure.

The FHWA deemed the bridge “seismically deficient” in 2019. An analysis determined that the more valuable option was to construct a replacement bridge upstream in a manner consistent with the surrounding landscape. The project also required contractor housing and a staging area to be located just beyond the landslide at Toklat Pit.

The FHWA awarded a contract in 2021 and work was scheduled to begin this summer. But when the Pretty Rocks landslide and subsequent road closure blocked access to Toklat Pit, officials determined it was too costly to relocate the housing and staging area to the east side of the landslide and the contract was “terminated for convenience.”

Officials say they will send out a new RFP for the Ghiglione Bridge project once Phase I of the Polychrome area improvements are completed and road access beyond the landslide is restored. Once started, construction is expected to take two years. Barring any significant seismic activity during construction, officials say the existing bridge will remain open during construction.

Amy Newman is a freelance writer who lives in Anchorage.