This area is know as the Alpine Tunnel Historic District which consists of a 200' wide right of way along 13 miles of the original Denver, South Park and Pacific rail bed between the town sites of Quartz and Hancock.
The hike follows the old railroad grade from the ghost town of Hancock to the East Portal of historic Alpine Tunnel, one of the great railroad engineering feats of the late 19th century.
At one time this was the highest railroad tunnel in the world and it was the first tunnel to be built through the Continental Divide. The tunnel entrance has collapsed (It required over 400,000 board feet of California redwood to support and encase 80% of it due to crumbling granite.), but views from the trail are spectacular.
It's a total of 5.8 miles out and back on a pretty easy trail. The trail starts out at the elevation of 11,044' and climbs to 11,582'. I added an additional 3+ miles on this hike by heading up to Tunnel Lake. There was still plenty of snow to cross but the the weather was perfect. I finally turned around at about 12,154' - according to my GPS - and slightly past the lake. Total time for this hike was about 5.25 hours including stops to take pictures and breaks to catch my breath, drink water, and snack. :)
