The range provides a formidable barrier to travel and is traversed only by backroad passes and trails, including Schofield Pass, Pearl Pass, and Taylor Pass. State Highway 133 traverses McClure Pass, at the western end of the range. The range has been the site of mining activity since the days of the Colorado Silver Boom, which saw the founding of mining towns such as Aspen and Ashcroft. In the late 19th century, the western and southern flank of the range became the site of intense coal mining activity which continues to the present day. Treasure Mountain, overlooking the town of Marble, is home to the famous Yule Marble Quarry. Quarried marble was used to create The Tomb of the Unknowns, the Lincoln Memorial, Denver Post Office and other buildings. The range receives a great deal of snowfall due to its position to the west of the continental divide and the westerly origin of many winter storms. This is exploited by the ski areas in the vicinity of Aspen, which are located on the flanks of smaller mountains alongside the Roaring Fork Valley.