A project that would clear up to 146 acres of forest for vineyards in northwest Sonoma County is nearing state approval. The controversial proposal, put forward by Napa-based Artesa Vineyards has been on the drawing board for more than a decade.

CalPERS has ended months of uncertainty by signaling to Sonoma County that it intends to move forward with a huge, controversial timber-to-vineyard conversion project near Annapolis.

Growing unease about a wave of vineyard projects that call for clear-cutting forested hillsides has Sonoma County officials calling for an emergency halt until new regulations are crafted. Sonoma County Agricultural Commissioner Tony Linegar has proposed a four-month moratorium on vineyard projects that would remove trees from ridge tops or slopes greater than 15 percent.

The state pension fund is parting ways with Premier Pacific Vineyards, a Napa firm that manages its portfolio of vineyard properties. Sources say the move threatens Preservation Ranch, the controversial 1,769-acre forest-to-vineyard conversion project in northwestern Sonoma County.

Beyond the dusty homesteads and small fruit orchards that ring the isolated town of Annapolis stand vast forested hillsides that long have been the domain of timber companies. But as logging has waned, the sprawling northwest Sonoma County landscape of second-growth redwood and fir is being eyed for another crop: premium grapes for top-dollar wines.