"In the 1930s, workers using explosives and machinery excavated a 13-mile tunnel beneath Mt. San Jacinto to bring Colorado River water to Southern California. The Metropolitan Water District recently offered visitors a look inside the tunnel, an engineering feat that is a key piece of the 242-mile Colorado River Aqueduct."
"Thousands of feet below the snowy summit of Mt. San Jacinto, a formidable feat of engineering and grit makes life as we know it in Southern California possible.
The 13-mile-long San Jacinto Tunnel was bored through the mountain in the 1930s by a crew of about 1,200 men who worked day and night for six years, blasting rock and digging with machinery. Completed in 1939, the tunnel was a cornerstone in the construction of the 242-mile Colorado River Aqueduct. It enabled the delivery of as much as 1 billion gallons of water per day.
The tunnel is usually off-limits when it is filled and coursing with a massive stream of Colorado River water. But recently, while it was shut down for annual maintenance, the Metropolitan Water District of Southern California opened the west end of the passage to give The Times and others a rare look inside."
Advertisement 
