Donner Pass Summit Tunnel
Where to park: Old Donner Summit Rd. Truckee, CA 96161
Trailhead: 39.314686, -120.326970
First Tunnel: 39.315793, -120.321747
Level: Easy to Strenuous depending on how far you want to hike.
The hike to the first tunnel is under a half mile.
Miles: The entire loop is 5.9 miles.