Mile Rock Tunnel is a utility tunnel in San Francisco, in the U.S. state of California that was originally constructed as the storm sewer outfall draining the Sunset, West Mission, Richmond, and Ingleside districts.

The tunnel travels from Cabrillo Street northward under 48th Ave to its outfall near Mile Rock Beach.

[2] The contract was initially awarded to Edward Malley, but he stopped work after five months because of the high cost of insurance; R.C.

The tunnel was fitted with temporary structures and lighting to allow the car to enter without the threat of flooding from the outlet, but as it was not wide enough to allow the car to turn around, the return trip was conducted in reverse gear.

[3] The tunnel was constructed by a combination of cut-and-cover (through soil) and boring (through rock) methods.