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Here's a little history on the line, from the above article:
The original Silverton Northern was built by Otto Mears, operating from 1895 to 1942, serving the mines between Silverton and Animas Forks.
It began at Silverton with two miles of Silverton Railroad track, and reached Eureka in 1896. It was extended up a 7 percent grade to Animas Forks in 1904 for a total of 12.5 miles.
The branch up Cunningham Gulch was built in 1905. A few trains ran occasionally on the Animas Forks section into the 1920s and regularly on the lower section to Eureka until 1939, when the Sunnyside Mine closed. The SN ceased in 1942 when the U.S. Army drafted three SN locomotives to serve its needs in World War II on the White Pine & Yukon in Alaska.
The San Juan County Historical Society announced its ambitious plan to rebuild the 2-1/2-mile section of the old Silverton Northern Railroad from the Powerhouse Industrial Park to Howardsville in August 2010.
Historical society officials said the idea underlying the rebuilding effort is economic development — to develop a locally operated passenger-excursion train based in Silverton.