“Seventeen is closed, Skyline is closed, nine is closed, 152 is closed,” my mom tells me at a restaurant in San Jose, Calif., rattling off highways between the San Francisco Bay Area and the Pacific coast, where I'm scheduled to drive the next morning. Last winter's torrential storms turned California's hillsides so sodden that they slid down over roads, cutting off communities. Between October 2016 and February 2017, the state saw about double the seasonal average annual precipitation. North of Sacramento, more than 188,000 people were forced to evacuate their homes as the Oroville Dam overflowed, eroding a giant crater into its spillway and threatening to release one of the state's biggest reservoirs. “I can't remember ever seeing it like this,” my mom says, echoing the amazement of millions of longtime Californians.