Jordan Thomas, a 25-year-old graphic designer who works for the Map Store in Windsor, may look like he's fresh out of high school, but he knows what he's talking about when it comes to cartography. Passing under layers of rolled maps stowed overhead, he strides through the store--a sea of globe key chains, globe-painted basketballs, GPS doodads and software, map magnifying glasses and fold-out maps of Missoula, Hanoi and noteworthy baseball sites--and finally arrives at his destination: a map.

This map is the eagerly awaited update of Sonoma County's American Viticultural Areas (AVAs), boundaries that differentiate wine-growing regions from one another based on terroir. Until now, the map hadn't been revised since 1997. Thomas estimates that Sonoma County wine-related agriculture has almost doubled and that some 60 percent of vineyard names have changed in the past decade. The Map Store took it upon itself to revise the map, relying on the Sonoma County Grape Growers Association (who had sponsored the 1997 edition) for help. The project took Thomas and others roughly one year to complete, and the result is a series of six maps focusing on different areas within Sonoma County ($29.95 each).

Since 1997, some of the AVA boundaries have changed. Thomas points to a jagged purple line on the map, which indicates the Russian River AVA's new limit. Thanks to a petition by growers, that prestigious AVA now encompasses vineyards around Santa Rosa and Sebastopol, allowing affected wineries to sell their products at higher rates. But looking at the map gets a bit complicated because of AVA overlap. Thomas points to one area that belongs to six AVAs.

Heading back to his desk, Thomas admits that the project had its challenges. He had thought it might be a good idea to collect the data he needed online; this way, it could easily be updated anytime. So the store set up a website, encouraging vineyard, winery and tasting-room representatives to submit their geographical coordinates via the Internet.

"We tried to make it easy, and for the most part, everyone was happy that we were doing this, but there were some we just couldn't please," says Thomas. "I'm 25 and I'm trying to explain to a 70-year-old man why he should use the Internet. The situation's set up for conflict."

Scott Lowrie, also 25, commiserates. Some wine professionals had particular trouble locating their assessor's parcel number, even though the Map Store had provided illustrated instructions on where to find it. Lowrie contributed a lot of the Geographic Information Systems work for the map, and says, "There were days when the phone wouldn't stop ringing; we couldn't get anything done."

Despite the meticulous detail and accuracy, Thomas doesn't have plans to send the maps to cartographical archives, like the treasured Map Division of the New York Public Library. He says there's no need. The maps are available online, and digital technology allows for frequent updates.

In fact, the Map Store is in the process of making a solely electronic map of Sonoma County that includes soil, climate data and parcel lines, "so you can get a feel for specific influences on each vineyard," says Thomas.

When the store management does actually want to print an edition of maps, they use their on-site printer to release updates whenever the need arises, rather than outsourcing massive batches. In fact, Thomas already plans to print an update to the Sonoma County AVA maps this spring.

Later, Lowrie sets to work, printing large-scale aerial photos. He dons a pair of white gloves and prepares a large roll of glossy paper to feed into a printer, which someone has affectionately labeled "MAPPY." Clearly, map lovers belong here.

The Map Store, 9091 Windsor Road, Windsor. 707.838.4290.

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