Routing Power to the Top of a Popular Skiing Summit

Big Sky Resort is a popular wintertime destination for alpine skiing enthusiasts, with more than 5,800 acres of snowy and mountainous terrain. Accessed by a suspended tram, Lone Peak is the highest point with a 11,166-foot summit. As part of reimagining the mountaintop experience, Big Sky Resort replaced a 27-year-old tram with the new Lone Peak Tram.

HDR designed and helped install an upgraded power system to service Lone Peak Tram as well as future expansion at the top of summit — a project made more complex because of the rough terrain and steep elevation.

Because the only access to the top of Lone Mountain is by helicopter or foot, running power to the top of Lone Mountain was a challenge. The installation also had to cover 2,200 feet in length with 1,300 feet of elevation gain. The power line previously servicing this stretch was insufficient for the bigger and more power-intensive installation.

We worked with a cable manufacturer to customise a solution that fit the project’s needs. Our team balanced the difficulty of installation — the cable needed to run continuously but still be light enough for a helicopter to pull and place — and power demand on the summit. We selected three separate armoured power cables, offering protection from external factors above ground while keeping each cable under the helicopter’s weight capacity.

During installation, a Chinook helicopter unspooled the armoured power cables and pulled them to the top of the mountain while workers attached them to temporary anchors at the top. After the three cables were in place and anchored at the top, they were manually attached to customised micropile anchors every 200 feet along the mountain’s face. At each end, cables entered splice vaults and were routed underground to a system of transformers and switches designed by our team.

Successfully powered, the tram opened to the public for the 2023-24 winter season and continues to run winter and summer rides, offering panoramic views of the surrounding mountain scenery.

The Lone Peak Tram built upon several years of successful projects we have completed for Big Sky Resort, including underground power line installations and medium-voltage designs.