The Spring Garden Tunnel is a railway tunnel located at Spring Garden, California. At 7,344 ft (1.3909 mi; 2,238 m) long, it is the longest of 34 tunnels on the Feather River Route (cf. Chilcoot Tunnel)[1] and crosses under the drainage divide between the East Branch North Fork Feather River (north portal, 39°53′15″N 120°47′02″W / 39.8876°N 120.7840°W) and the Middle Fork Feather River (south portal, 39°52′07″N 120°46′30″W / 39.8686°N 120.7750°W).
The Western Pacific line between Oroville and Chilcoot has thirty-four tunnels. ... Spring Garden is 7,344 feet in length and the Chilcoot tunnel is 6,002 feet.