Beckstoffer has figured out that a certain altitude--from about 600 to 730 meters--in the right part of Lake County has a heating-and-cooling cycle similar to Napa's.

FORBES: Magazine Article

Not that most wine drinkers had an opportunity to distinguish the difference between the two as most Lake County grapes were added to blends of various grapes from various places, including Napa Valley.

WSJ: Lake County, Napa's Neighbor, Gains Respect | On Wine