The Ukiah Daily Journal reports that the county's Board of Supervisors on Tuesday voted unanimously to make the declaration, citing an "imminent threat of disaster" from drought conditions.
The state Department of Water Resources said Mendocino is the first to request state drought assistance.
Officials hope the declaration will result in state funds and assistance in developing a drought plan.
Gov. Jerry Brown has convened a task force to help decide if a statewide drought emergency is warranted.
State water managers say they will be able to deliver just 5 percent of the water sought by municipal agencies and nearly a million acres of farmland.
The USDA is providing disaster assistance to beekeepers in California. The money may help some stay in business.
As the forecast for a wet December improves, a new study says only so much water can be stored by future dam or reservoir projects in California.
The National Weather Service is offering a more positive forecast for the likelihood of a wet December in California.
(AP) - Officials say residents of a California community where hundreds of home wells have run dry can now take hot showers in portable facilities set up in a church parking lot.
The U.S. Drought Monitor measures the impact of the drought across the nation and California cattle ranchers have millions of dollars at stake based on that information. But some are questioning the accuracy of the data.