For evidence of that mineral abundance, look no further than Irwindale, home to more than a dozen massive pits emptied last century for those critical building components.
But now, as another building boom rumbles across Los Angeles and a new generation of high-rises climbs skyward, the rock and sand are coming from a much more distant source: Canada’s Vancouver Island, more than 1,400 miles away.
That’s a long distance to ship commodities that are still abundant locally, sell for less than $20 a ton — and often cost more to transport than to mine.
Yet thanks to a combination of materials science, cheap ocean shipping and, some argue, NIMBYism, today’s industrial concrete mixers are often filled with imported rock and sand.
Timely, incisive articles delivered directly to your inbox.