The wrong-way driver was identified as Ramon Valencia Jr, a 34-year-old man from Santa Paula.
Police said Valencia slammed into a car driven by 25-year-old Brandon Thompson of Riverside. The passenger in Thompson's vehicle was identified as 28-year-old Rachel Cline of Lake Elsinore. Their dog was also killed.
The violent wreck happened on the southbound 101 Freeway near the Seaward Avenue exit at 12:03 a.m. Thursday.
A California Highway Patrol officer spotted Valencia's Toyota Scion getting on the freeway in the wrong direction at a very high rate of speed. According to police, Valencia was driving nearly 100 mph.
The officer tried to keep pace with the car on the other side of the freeway while calling additional units to help him, but it was too late. Valencia, Thompson and Cline were all pronounced dead at the scene.
The Ventura Fire Department says both cars were mangled. One went over a guardrail and the other came to a rest about 50 yards north of the crash.
Authorities are looking into whether drugs or alcohol played a role in the incident. Anyone who witnessed or has information about the crash is urged to call the Ventura Area CHP office at (805) 662-2640.
A GoFundMe account was started to help the families pay for funeral expenses for Thompson and Cline: https://www.gofundme.com/narc7q-funeral-expenses
The Associated Press contributed to this report.