Fatal wildfires scorching eight Northern California counties this week have dealt a devastating blow to the important wine and tourism industries, destroying several historic wineries and threatening the remaining grape harvest in the Napa and Sonoma valleys.

Although the seasonal harvest is nearly complete, the conflagration threatens to disrupt tens of thousands of jobs and destroy valuable stores of grapes and wine in bins, barrels and bottles. The extent of the damage will be unclear for days because the fires are blocking many worried owners from reaching their wineries.

Tourism in the region — a multibillion-dollar economic machine that includes high-end hotels, wine-tasting tours and upscale cuisine — is suffering as the flames have claimed a number of establishments and forced many others to shutter for the rest of the week.

“It has been a devastating fire,” the Sonoma County Winegrowers group said in a Facebook post. “Reports of fire damage to wineries, businesses and homes continues to grow.”