The first auto road across the northern Colorado Rockies was begun in 1913 with convict labor and completed nine years later. Because of its narrow track with steep switchbacks and hairpin curves, it was converted to a one-way motor nature trail in 1968. The partially paved route is lined with ruins of three convict labor camps. At the northwest corner of Willow Park is the Willow Park Patrol Cabin and Stable (1924), a two-room saddle-notched log cabin with exposed logs, rafters, and decks inside what were the kitchen and mess hall for Fall River Road construction crews. Near the 11,749-foothigh junction of Fall River and Trail Ridge roads is an enduring piece of Alpine architecture, Timberline Cabin (1925), a small, low-slung, functional pile of local rock with logs and rocks holding down the roof. Fall River Pass Ranger Station (1922) is a 16-by20-foot rubblestone cabin dug into the rocky tundra slope under closely spaced log pole rafters, with a trap door in the roof for access in deep snows.