The statewide ballot initiative to label genetically engineered food known as Proposition 37 was soundly defeated on Election Day but drew strong support along California's liberal coast.

While trounced by voters statewide 53 percent to 47 percent, the measure was endorsed by more than 65 percent of voters in San Francisco, Santa Cruz and Humboldt counties. It was rejected in nearly all of the more conservative inland counties, including the state's agricultural center of Fresno, Kern, Kings and Tulare counties. In Fresno County, 63.6 percent voted no while 36.4 percent voted yes. The measure won in farm-heavy Imperial County and the Sierra Nevada mountain counties of Mono and Alpine.

The geographic divide highlighted the challenges that Proposition 37 had reaching and appealing to voters in more rural and conservative parts of the state, particularly in counties where agriculture is a huge part of the local economy.

"This is a story about money," Stacy Malkan, media director of the Proposition 37 campaign, said Wednesday. "Our loss had to do with being outspent. We didn't have the funds to compete on the air in the central regions of the state."

Kathy Fairbanks, a spokeswoman for the No on 37 campaign, said Wednesday that initiative supporters underestimated the views of California farmers.

"We had the overwhelming majority of groups representing family farmers and those who depend on California's agriculture industry," Fairbanks said. "They didn't like that Prop. 37 would have put family farmers in California at a competitive disadvantage."

Supporters of Proposition 37 said Wednesday that efforts to require labels on genetically modified foods are now shifting to other states. Signature gathering is under way for a similar ballot initiative in Washington state in November 2013, along with legislative efforts to require labeling in Connecticut and Vermont.

A petition effort is also under way to get the federal Food and Drug Administration to take up the issue of labeling. There will also be renewed pressure on President Barack Obama in his second term to support labeling.

In a postelection conference call with journalists Wednesday, the Yes on Proposition 37/California Right to Know campaign said the election results, while disappointing, were not surprising given the $46 million raised by the No side.

St. Louis-based Monsanto, a leading maker of genetically engineered seeds, was the largest single contributor with $8.1 million. The Yes side raised $9.2 million, with the largest contribution coming from Joseph Mercola, a popular holistic health activist from Illinois.

"We fought Monsanto and DuPont to a standstill last night," said Dave Murphy, executive director of Food Democracy Now. "More than 4 million Californians are on record saying they want to know what's in their food. This is a dynamic moment for the food movement."

Contact Dana Hull at 408-920-2706. Follow her at Twitter.com/danahull.

Prop. 37 election results
For county-by-county election results for Prop. 37, go to http://vote.sos.ca.gov/returns/maps/ballot-measures/prop/37