(Wine Searchers) - Growers are keeping an anxious eye on two large fires in Wine Country.

A big wildfire has crossed over into Napa County, less than a year after the region was devastated by one of the worst fire outbreaks in northern California history.

The air was brown in San Francisco, about 60 miles south of Napa County, on Sunday morning from smoke from two Wine Country fires: the County Fire, which started in Yolo County east of Napa, and the Pawnee Fire in Lake County north of Napa.

The County Fire is huge: 44,500 acres as of Monday morning, with only 3 percent contained. It is already larger than the Tubbs Fire that last year devastated northern Napa Valley and neighboring Sonoma County, and it is growing at a faster rate than that fire. Cal Fire believes it started in dry vegetation; the cause is under investigation.