The only prehistoric human remains uncovered in the Rancho La Brea area were those of the La Brea Woman, found in 1914. Excavators uncovered a woman's skull and partial skeleton. She was determined to have died about 9,000 years ago, making her one of the earliest identified human residents of Los Angeles County. She was believed to have been about 18-24 years old and stood about 4 feet, 8-10 inches (1.5 meters) tall. Wear on her surviving teeth indicated a diet of stone-ground meal. Her skull structure indicated that she may have been of the Chumash people, though, this is debated. Also inclusive is whether she was originally from area of the tar pits. Her skull was also found fractured, suggesting a blow to the head that may have killed her. She might just be L.A.'s first known homicide victim. A broken grinding stone was found nearby (a common burial item among Southern California aboriginal people). The remains of a domestic dog were also found nearby, long believed to have been buried with La Brea Woman, perhaps as part of a ceremonial process. The dog's remains, however, were later determined to be only about 3,000 years old.
Source: The Page Museum at the La Brea Tar Pits (and thanks, Claire, for your notes!)
In 2009, forensic artist Melissa R. Cooper created a facial reproduction of what La Brea Woman's face may have looked like, based upon her skull structure.