Tunnel No. 41
Tunnel Number 41, or the Big Hole, is a single-track railway tunnel underneath Mount Judah in the Sierra Nevada, near Norden, California. It is owned by Union Pacific Railroad, in service as a part of the Roseville Subdivision of the Overland Route. Daily freight trains as well as Amtrak's "California Zephyr" utilize the line. Built by Southern Pacific to bypass the curves over Donner Pass along the First Transcontinental Railroad, it opened to traffic in 1925 as the third-longest rail tunnel in the United States at in length. The new tunnel and cutoff shortened  the route by and was lower in elevation than the previous bore through the summit, Tunnel No. 6. The new and old single track routes were used in tandem as a double-tracked route until the old route was abandoned in 1993. The line is capable of transporting double-stacked containers.