The U.S. Geological Survey says a magnitude-5.5 quake struck at 1:07 p.m. about 18 miles east of Trinidad in an unincorporated part of Humboldt County.
The epicenter is a rural area near the small community of Weitchpec, about 220 miles northwest of Sacramento.
A dispatcher at the Humboldt County Sheriff's Department says the temblor was widely felt and the shaking lasted 30 to 45 seconds.
Hundreds of people reported feeling the quake on the USGS website. Some are as far away as southern Oregon.
The sheriff's dispatcher says there are no immediate reports of injury or damage, but deputies are going out to check on residents.
Stay with Action News and ABC30.com for more on this Breaking News story.