Argentine Central Railway

The Argentine Central Railway was a narrow gauge railroad in the United States built from the Colorado and Southern Railway at Silver Plume, Colorado, to Waldorf, Colorado, (now a ghost town) and onward to the summit of Mount McClellan. Construction began on August 1, 1905, and the line was opened to Waldorf a year later on August 1, 1906, a distance of about 16 miles. It was financed and organised by Edward J. Wilcox, owner of 65 mining properties in the Argentine region that were consolidated into the Waldorf Mining and Milling Company in 1902. His headquarters at Waldorf was accessible only by pack mule for much of the year. As well as serving the silver mining operations of the region, the railroad was also intended for the tourist trade, ascending Mount McClellan and intending to reach the summit of 14,270 ft (4,350 m) Grays Peak nearby. It was believed at the time that Mount McClellan was high, but this was later disproved. It remains the highest altitude reached by a regular adhesion railway (as opposed to a rack railway) in the United States. The line was steeply graded and sharply curved, with a standard of 6% grade maximum and 32° minimum curvature ( radius); even so, it required six switchbacks on the ascent. Due to these grades, geared steam locomotives were used exclusively, the railroad rostering a total of seven two-truck Shay locomotives. As well as ascending to Argentine Pass and Grays Peak, Wilcox purchased the Vidler Tunnel, a project begun in 1902 to expand an existing silver mine into a railroad tunnel under the pass. The line would have extended onward to Keystone, Colorado, and a junction with the Denver, South Park and Pacific Railroad. Work on the project stopped in 1911, by which time the tunnel was three-quarters completed. The tunnel project was revived as a highway tunnel in 1952, and the 1.4 mile tunnel was completed as a water diversion tunnel in 1969.