Authorities have identified the drivers killed in a head-on crash early Sunday morning near Buellton as Marjorie Moore, 73, of Lompoc and James White, 39, of Solvang.
The vehicles collided on Highway 246 at Domingos Road at approximately 3:30 a.m., according to the Santa Barbara County Fire Department.
The California Highway Patrol says White was driving "at a high rate of speed" when he crossed into the oncoming lane and crashed into Moore.
One of the vehicles was found overturned on the road and the second had gone over the side and down an embankment, fire officials say.
Both drivers were pronounced dead at the scene. No other victims were found.
CHP says DUI is suspected as a factor in the crash, which remains under investigation.