Mentryville and Pico Canyon

Charles Alexander Mentry drilled three wells in this canyon that came to nothing before the fourth one paid. Pico No. 4 — CSO 4 on the state's marker — was completed on September 26, 1876, and it did not stop producing until 1990, a hundred and fourteen years later. It was California's first commercially productive oil well, and for a long stretch it was the longest continuously operating well anywhere in the world. The company that formed around it became Pacific Coast Oil, then Standard Oil of California, then Chevron.

Mentryville is what grew up below the well: a company town that housed more than a hundred families at its height, with Mentry's thirteen-room house, the barn and the Felton School still standing. It emptied out by the 1930s and spent decades as a ghost town with a caretaker living in the big house. The Santa Monica Mountains Conservancy runs it now and has left a good deal of rusted machinery lying where it lay, which was the right call. The well is not at the parking lot — it sits about a mile and a half further up the paved canyon road, which is gated to cars and open to anyone walking or riding a bike. Mentry died of typhoid fever in October 1900, and the town did not long outlast the century he built it in.