The San Benito Mountains boast two Superfund sites—New Idria mercury mine and Atlas asbestos mine—just 60 miles from a bike-friendly Amtrak station. Thanks to unusual serpentine geology, the area is dissected by mine roads in search of cinnabar, asbestos, and the rare gemstone benitoite. With lonely roads and star-filled nights, a bike traverse of the San Benitos is a grand adventure.
Historically the second largest mercury mine in the United States, New Idria now leaks heavy metals into Panoche Valley and the San Joaquin River. Panoche is home to Mercy Hot Springs—my first stop of the tour—and a glittering new solar farm.
There is no such thing as clean industry. The signs hung on barns and fence posts demanded, “Stop Solargen, Save Panoche Valley.” Behind the hand-painted signs, gleaming solar panels sprawled across the valley. A stream of vehicles caravanned workers home to the Central Valley.
Despite construction traffic, Mercey Hot Springs was still a desert oasis. For a steep entrance fee, I poured myself a hot tub and fell asleep to long-eared owls whistling in the pines.
From the hot springs, a white PG&E pickup truck was the only traffic on the road to New Idria. We leapfrogged each other, him inspecting power lines, me surveying prairie dogs. At the mine, where the tailings pond overflowed into the creek, he turned around and offered me extra water. But with the big climb ahead and my bottles still full, I declined.
Regretful. Late in the day I hung a left climbing out of Aurora Mine, one of many mineral claims dotting the New Idria district. It was dusk and soon just a sliver of moon lit my way. The wide jeep track climbed the open ridges—serpentine barrens too toxic for plant life. I pushed my bike up a steep and rocky path, exhaustion sinking my steps.
I made camp on the ridge and saved the last mouthful of water for morning. There was an orange left in my pack and I sucked each wedge like a sailor long at sea.
I was marooned on a mountain of asbestos. The moon sank lower every time I started awake. Meteors flashed. Constellations wheeled. Cygnus the swan, Cassiopeia, the Pleiades, and Orion shooting his bow. Then Big Dipper rose in the east. When next I woke, it was light.
By day, I could see I was headed much too south toward Atlas mine, the second Superfund site. I retraced my route across the serpentine and a beautiful stand of Leather Oak (Quercus durata) that made me glad for a second look in daylight. It was a decadent shrub, with coronated acorns and golden-silvery leaves.
Above Aurora Mine again, I took the now-obvious BLM road. It was a thrilling descent through fault-scarred hills headed west for the San Andreas fault. At the bottom Clear Creek flowed brightly through pine, oak, and chaparral. Clear and still undrinkable.
It was another hour of climbing into the next watershed. Finally I came to a roadside creek full of minnows. I shook off the serpentine dust, took a long deep drink, and pedaled away from the San Benitos.
Route: The New Idria Superfun(d) tour is a 180 mile ride starting in Gilroy and ending at Salinas, both Amtrak bus stops. See route. Suggested Itinerary (mileage is approximate):
Day 1: Gilroy Amtrak station to Mercey Hot Springs in the Panoche Valley, 60 miles. Tent camping is $40, best to reserve ahead on the weekends.
Day 2: Mercey Hot Springs to Oak Flat Campground in the Clear Creek Management Area, 45 miles. There is contradictory information about whether or not you need a permit to travel in the serpentine zone. I purchased a $10 permit online. My route takes you on unpaved roads past New Idria Mine and a side trip through Aurora mine, using Ray Hosler’s partial topo to navigate confusing mine roads. I read the map wrong at dark and ended up sleeping in the middle of the trail.
Day 3: Clear Creek to Pinnacles National Park, 35 miles. Camping at Pinnacles is crowded on weekends and holidays. The park condors catch thermals every afternoon off the ridge above the campground for your viewing pleasure. Plus, enjoy a hot water coin shower and ice cream sandwiches at the camp store.
Day 4: Pinnacles National Park to Salinas Amtrak station, 40 miles partially on dirt via La Gloria Road. The final stretch into Salinas has fast-moving traffic and headwinds.
Water: On Day 2, there is no drinkable water within the serpentine area or at campgrounds. Fill up at the hot springs and carry extra. While your camping filter likely removes asbestos, it will not remove heavy metals such as mercury. Travel during a cool time of year and know your water risk.
Season: Spring, fall, and winter for the best riding weather. I waited four years for a dry week of Thanksgiving. It paid off with stellar fall weather and clear skies for a view of the Leonid meteor showers. Scorching hot in the summer, not recommended.
Hazards: Asbestos, mercury, white supremacists—I spotted a swastika hailing Trump on gun-friendly BLM land—and wanderlust.