For the Hobby:
Silverton Railroads Data Map - Courtesy of Joe Weigman
Clever Models - Printable cardstock structure kits
Denver, South Park & Pacific RR (Includes Colorado & Southern NG)
Tuolumne City Museum (For Westside Lumber Company)
3' Narrow Gauge Tourist Railroads:
Leadville Colorado & Southern - Not currently narrow gauge, but once was part of the C&Sng mainline!