Big Valley District is located in a wide valley on the southwestern shores of Clear Lake, bordered by the Mayacamas mountain range to the west and south and the dormant Mount Konocti volcano to the east. The AVA only covers the flatter half of the valley north of Kelseyville and the more mountainous topography south of the town is part of the Kelsey Bench AVA. Big Valley is a structural basin that is part of the larger Clear Lake basin.