Yellowstone National Park hosts approximately 4 million visitors each year, many of whom elect to stay overnight. Of the Park’s several accommodation areas, Canyon Lodge and Cabins is the largest, offering approximately 500 beds including the cabins. The National Park Service decided to undertake a two-year redevelopment of the aging Canyon Village Lodge. The old cabin complex was demolished and five new three-story buildings were built, providing more than 400 rooms including two-bedroom suites. The 360 Engineering team provided heating and ventilating systems for the new buildings, including the main lodge of approximately 38,000 square feet. A unique aspect of the project was its use of pre-fabricated rooms and systems that were dropped into place, where the mechanical systems were connected and completed on site. Some of the system highlights include high-efficiency condensing boilers to optimize efficiency and reduce pumping horsepower; a heated water system sized to support the building’s large domestic hot water load; and, to facilitate winterization, a gravity-fed drain down system (plumbing and hydronic heat) for entire lodge. The challenges presented by winterization – performed by a skeleton crew in a harsh climate — required significant coordination with the integrated team. Buried by snow in the winter, the lodges re-open with snow pack, making access to the mechanical room another concern. Over multiple site visits, 360 Engineering reviewed the developing design with Yellowstone’s head maintenance personnel. With their input and close work with the architect and equipment manufacturers, we delivered effective, efficient mechanical systems that met all client goals and obtained LEED Gold certification for four buildings and LEED Silver for the registration building and lodge.