In the center of the picture is a railroad bed that was carved through the solid rock. Most of the workers
on the railroad were immigrants. Many were Irish and Chinese. A number of them died while setting
dynamite charges to bore through the mountains. The wooden structures are sort of snowsheds that
allowed the trains to run in the winter - the snow would pile on top of these structures keeping the tracks
clear. The line is abandoned now, and is used as a very scenic biking and hiking trail.
To read more about the history of this railroad line go to the Central Pacific Railroad Museum website at:
http://www.cprr.org/Museum/Sierra_Grade_8-2003/Donner_Pass-Summit_Tunnel/