As linked in WineTerroirist, KelliWhite has a terrific article in GuildSomm:
on making Making Sense of Mendocino. Very well researched, very well written...a must-read.

Although the AndersonVlly is the most well-known AVA in Mendocino, she points out the tremendous/unrealized potential the inland valley has for (once again) making great Mendocino wines.
There are a bunch of sub-AVA's in MendoCnty that I'd never heard of, nor seen on a label ever. I was unaware how much area the MendoRidge covers, though the actual AVA, above 1,200 ft elevation, is still pretty small.
The article points out that many of the grapes go out of the County to Napa/Sonoma to flesh out the 15% slop in the AVA-labeling.
One of the things I didn't realize is that the City of Ten Thousand Buddhas, once owned by Andy Beckstoffer, was once a Calif state (mental?) hospital. It's a beautiful property that Andy made a huge mistake when he sold it, I think.
I, of course, have followed MendoCnty wines from the very start. When BarneyFetzer released his first Zins in '72. I pine for the days of the great Green Hungarians from ole Fred Weibel. Make no mistake, MendoCnty can make great wines every bit as good as any area in Calif. The CortiBros Reserve(Edmeades) '78 remains one of the greatest Calif Cabs I've ever had. The Cabs & Zins from JedSteele at Edmeades, mostly MendoRidge, were stunning. The Zins/Cabs/Petites from Milano were outstanding. The early McDowellVlly Syrahs, made by John Buchenstein, were as good as any ever made in Calif. This is, of course, now the GibsonRanch owned by the Bilbros. Some of the Rieslings from ColeRanch and Guinness McFadden's McFaddenRanch in PotterVlly are as good as it gets.
The article mentions the Coro Mendocino wines. I've not read anything about those wines in ages. I thought the project was dead, if not comotose. Anybody know where you can buy that set of wines?? I'd like to try them again.
Visually, MendoCnty is absolutely beautiful. My heart always skips a beat as I drive over that rise and drop down into the UkiahVlly. Lots of very fond memories of my times up in MendoCnty. Sitting around the table at Lynn & Casey Hartlip's up on EaglePointRanch, PeeWee dozing away off in the corner, James and Bob grunting away in their pigpens off in the distance. Great times, indeed. I need to get back up there again.
Anyway, Kelli has written a terrific article that's worth reading.