On July 4, 1983, the D&RGW opened a new mainline through the Thistle Tunnel, bypassing the old town of Thistle buried beneath a 300 foot natural dam and submerged beneath a new lake. The first through trains (#178 and #101) are pictured at the west portal of the 3009 ft. tunnel. Highway builders have their work cut out for them relocating US Highway 6 along the north face of Billy's Mountain.
