Train Tunnels features 10 miles of hiking trails near Truckee, CA.
Heading on eastbound I-80 exit at \"Soda Springs Norden\" and take a right on Donner Pass Rd. Continue past the flashing red light to the road going to the Judah side of Surgarbowl, there is a surgarbowl sign on the corner. Immediately takea right and you will see a tunnel go under the road. Thats the begining of the ride.
http://www.tripleblaze.com/trail.php?c=3&i=1931