Explosion through Mount Jacinto completes the water tunnel. California, America.
Item title reads - California.
Blasting a funnel through Mount Jacinto. America (USA).
L/S of Mount Jacinto. M/S of engineers making a tunnel far below which will be used to carry water from the Colorado river to Southern California. They have been working from different ends and are nearly all the way through the mountain. C/U of hand flicking switch which blasts away the last of the wall between them, M/S of explosion. The engineers cheer and climb over the rubble to greet each other.