A 75-passenger tram now provides skiing and scenic access to the top of Lone Mountain at Big Sky Resort. Crews built a 8,828-sq-ft bottom terminal building and an 8,828-sq-ft loading platform, with a base elevation of 9,025 ft and top elevation of 11,166 ft.

More than 30 construction, design and engineering firms from around the world collaborated on this project, requiring a high level of strategic planning, modeling and execution. The embeds and lift alignment had to be accurate within 2 mm to ensure the tram equipment would function properly. Surveys were performed before, during and after concrete placement to ensure accuracy.

Lift manufacturer Garaventa designed the terminal building’s large mat footing, which sits on six rock anchor tie-backs and 17 micropiles. Meanwhile, a 100-ft-tall intermediate tower sits at an elevation of 500 ft to help the tram clear the cliff bands. Atop those cliff bands among steep terrain, the tower sits upon three foundations, which include 24 micropiles and two rock anchors.

Photo courtesy Jimmy Neu

With no road access to the top of the mountain, the majority of materials were delivered by helicopter, including the cranes, skidsteer, mini excavator, drill rigs, rebar and concrete. Crews had to hike up and down the mountain. Although the lower terminal could be accessed via a steep winding gravel road, stuck trucks and flat tires made this a challenge.

The top terminal could only be accessed via helicopter and an old tram, which did not have the capacity to haul materials. These difficulties were compounded by limited helicopter availability in the heart of fire season. The team coordinated with seven helicopter companies to ensure the right equipment and skill sets were available for each task. Chinook helicopters erected the project’s two tower cranes, lifting pieces as heavy as 10,000 lb, and transported 12,000-lb generators to run them. Once in place, these cranes set embeds and erected the tram steel. Since cranes are not designed to be erected via helicopter, creative solutions were required to ensure appropriate safety measures were in place. The team successfully brought 9,000-lb beams to the peak and erected them with the two tower cranes.