Santa Barbara County Sheriff's Lt. Butch Arnoldi tells the Santa Maria Times that 54-year-old Sara Ornelas and 49-year-old Barbara Romero were driving to a casino at 11:45 p.m. on Dec. 21 when they pulled over west of Lake Cachuma.
Officials believe that when one of them opened a door their small dog jumped out into traffic on Highway 154 and was struck.
One of the women went to retrieve the dog and also was struck.
Arnoldi says the other woman went to save her companion and was struck multiple times.
Both women and the dog were fatally injured.