Monday March 10, 2025
Sierra Club —
Roger Castillo drives his dented Ram pickup truck on a steep-sided levee. We are only a few miles from downtown San Jose, California, in a landscape of warehouses and small bungalows. Below, a silty creek flows through heaps of garbage, concrete debris, and countless plastic bags. Along the opposite bank stands a makeshift structure built of cast-off wood and tattered tarps.
Castillo, a former mechanic, is a self-trained naturalist. He grew up in San Jose and has lived here all his life, studying the bounteous life amid the nooks and crannies of the South Bay’s urban terrain. His best-known discovery came back in 2005, when he found a fully intact wooly mammoth fossil in an embankment on the Guadalupe River, minutes from downtown. (A statue of “Lupe” the mammoth commemorates the find.) On this cloudy late-November day, Castillo is scanning the murky water for something seemingly as improbable as a mammoth. He is looking for Chinook salmon.
It’s not long before he spots one, stranded on its side in a section of the riverbed covered in concrete. When Castillo sees the fish, he slams the gear shifter into park and leaps from the car nearly before the vehicle has stopped. My son, Owen, 16, seated in the pickup bed atop a large cooler, braces himself on the sidewalls to keep from being thrown asunder. For a man in his early sixties, Castillo moves with great speed, wriggling into his waders and shimmying down the steep hillside before we’ve even had time to slip a toe into our own waterproof gear.