Two hundred and fifteen acres in Valley Ford will be protected from development in perpetuity, after Marin Agricultural Land Trust purchased its sixty-sixth conservation easement last week. The owners of the Mazzucchi Ranch, Stan Mazzucchi and his sister, Loretta Bidarruta, accepted $424,000 for forgoing their right to subdivide or develop. They will continue raising 300 head of sheep, and will use the funds to improve and expand their operation. “This well cared-for ranch is a…