I’VE BEEN SPENDING some time in wine country recently, renting a cabin from friends.

Every morning I sit out on the deck, drinking coffee, reading, and admiring the view, which you can see in a photo below. In the time I’ve been here, the vineyard across the way has turned from sparse and brown to bushy green, and that got me wondering: Whose vineyard is it? What kind of grapes are they growing? Is the wine any good?

In trying to figure that out, I eventually stumbled on a map-driven website for wine industry insiders. It was developed by Jordan Thomas, a cartographer who grew up here in Sonoma county. Jordan was quick to tell me that the point of his site isn’t to satisfy the idle curiosity of wine country visitors like me–it’s used mainly to help match vineyards that have grapes to sell with winemakers who might be interested in buying them. That said, it’s a also a great way to satisfy the idle curiosity of wine country visitors like me.