Some of the more significant CCC features included development of the road system (gravel surfaced) to accommodate automobiles, Adirondack lean-to shelters, the Thunderbolt Ski Shelter, and completion of Bascom Lodge. As a result of increased popularity of winter recreation and downhill skiing, the Mount Greylock Ski Club initiated a plan to create a challenging ski run on Mount Greylock. The planning skills of Dwight J. Francis and Western Massachusetts Winter Sports Council, including input from Williams, Amherst, Smith, Mount Holyoke, and Massachusetts State Colleges, Greenfield Outing Club, and the Green Mountain Club, resulted in the CCC building the Thunderbolt Ski Trail in 1934 (named for its resemblance to a Revere Beach, MA, roller coaster). The lower section of the Thunderbolt Trail was relocated in 1936 by Charles L. Parker. This ski trail was rated "Expert-Class A" by the United States Eastern Amateur Ski Association (USEASA, today the United States Ski and Snowboard Association) and later host site for the USEASA Championship Races in 1938 and 1940. The trail was used for numerous competitive downhill ski races up until 1959.