The earthquake occurred just after noon and was centred off the coast about 337 kilometres northwest of San Francisco, just off a tiny town called Petrolia that's home to fewer than 1,000 people.
Wolf, director of Sonoma County Reptile Rescue, said he crawled under mountainside home in Santa Rosa and found a rattlesnake right away, then another and another.
The Caldor Fire in the northern Sierra Nevada already destroyed dozens of homes, and authorities on Friday closed down a 46-mile (74-km) stretch of Interstate 50, the main route between the state capital of Sacramento and Lake Tahoe on the Nevada state line.
Dozens of wildfires raging throughout Northern California have now claimed at least three lives, including the first civilian, and threaten tens of thousands of homes, authorities said Thursday.
An earthquake of magnitude 5.6 jolted the coastal region of Northern California, the United States, on Monday.