To get to Glass Beach, you turn toward the ocean at the Denny’s on the outskirts of Fort Bragg, Calif., and drive down the lane to park. Signage is minimal. This is not Big Sur.

The day we go, two local guys drive up and park next to us in a Volvo that has seen more than its share of ocean salt. "Need a bag?" one of them asks when he sees me rummaging in the lunch supplies. He hands me a grocery sack from a bunch inside the rusted trunk, then heads down the path towards the craggy headland. We follow him along the edge of the abandoned town dump.

Near the cliff scarp where land gives way to the Pacific, the ground has been recently bulldozed, covered with a layer of sandy soil. We trudge across the loose dirt and pick our way down to a small, rockbound cove. The ocean pounds into the beach in the intimidating way it does along the West Coast. Waves boil hard over rocks, slam into crannies, suck out with fierce power. It makes me reach for the kids’ hands.

The tide is still high. Only a foot or two of beach is exposed, and we cling to a strange-looking ledge of sediment. The ledge is rust-brown, hard as sandstone, and unlike any rock I encountered in geology class. I coin the term "dumpstone," since it seems to be made up of consolidated garbage. The "rock" is a matrix of dark grains and metal tire rims, fragments of broken plates, the battered remains of a metal cigarette lighter, chicken bones, automobile springs, a doll’s head, the innards of a clock radio.

What we can see of the beach looks like wave-worn glass. The kids can’t resist flirting at the edge, lured by the sparkling glass, running back away from the next charge of ocean. They are wet to mid-calf in no time. In one cove where the kids have to climb on dumpstone to get far enough in to be out of the reach of waves, they find a cluster of old marbles rolling around together.

There are several coves where the old dump abuts the Pacific, where the ocean has torn open the treasure trove of another generation’s castaways. As luck has it, the tide is ebbing, exposing more and more beach, an expanse of glass winking wet in the sun. I pick a spot that’s still damp but safely out of the reach of surf, and lie down on my belly.

It’s surely sterile, I think, doused in salt. My hands comb through the broken jewels of old bottles, plates, toys, stuff from the kitchens and bedrooms and dinner tables of people whose descendants may live in the houses we drove past. The glass layer is several inches deep, mixed with sand. Among the glass, there’s a rubber tire from a toy truck, a watch spring, a worn glass doorknob.

A few collectors roam the beach, recognizable by their undistracted air. No lying on the belly for these folk. They know which colors to pick out, which fragments have value. Some of them, I suppose, decorate their windowsills and gardens with their finds. Others specialize in turning one man’s garbage into another man’s collectible.

Rooting about on Glass Beach is both fascinating and faintly repulsive. The glitter of it, the memories culled up — how I remember mastering the one-handed flicking open of a metal cigarette lighter as a 14-year-old, the schoolyard games of marbles, a forgotten toy. At the same time, this is dumpster-diving once removed. There is, too, something eerie about the place. It offers a glimpse of the geologic layer our species is destined to leave behind. Glass Beach is a suggestion of what will surely be a future geologic strata thick with stuff, one studded with jet engines, Wal-Mart signs, train cars, SUV door handles, what’s left of the Space Needle, and my mailbox.

Millions of years from now, imagine the theories that might surface to explain the remains of a jetski at the base of the arc of Hoover Dam, or the neon facade of Caesar’s Palace. The Leakeys of the next epoch have their work cut out.

At some point, before the tide turns, my family has had enough. Besides, the bag is almost full. I brush the shards of dumpstone from my pants and climb up through the hard layer away from the Pacific, a paleontologist ahead of his time.

Alan Kesselheim is a contributor to Writers on the Range, a service of High Country News in Paonia, Colorado (hcn.org). He lives and writes in Bozeman, Montana.