Oak Mountain is a mountain in the northern Peninsular Ranges System, in Riverside County, in southern California.
Oak Mountain consists of a mountain with two peaks, the northern at 2706 feet / 825 meters, taller than the southern at 2126 feet/ 648 meters, which is located east of the city of Temecula, dividing Pauba Valley from Butterfield Valley. The two peaks of the mountain are divided by the gorge of Temecula Creek Canyon which has Vail Lake Dam at its head. Vail Lake reservoir is to the east of its southern peak and southeast of its northern peak and at the base of the mountain. The Black Hills lie to the north of the mountain and Agua Tibia Mountain lies to its south.
The northern peak is located at 33°30′57″N 116°58′38″W / 33.51583°N 116.97722°W The southern peak is located at 33°29′11″N 117°00′40″W / 33.48639°N 117.01111°W