She was born and raised in Poughkeepsie, New York, and travelled to Palo Alto, California in 1963 with her older brother Don shortly after she was expelled from high school. In early 1964, Garcia met Neal Cassady, who introduced her to Ken Kesey and his friends, one of whom gave her the name ""Mountain Girl"". Cassady took her to La Honda, California, Kesey's base of operations, where she quickly joined the inner circle of Pranksters and became romantically involved with Kesey, having a daughter by him named Sunshine. The Grateful Dead song ""Here Comes Sunshine"" may or may not be an allusion to Garcia's and Kesey's daughter – the Dead were fond of lyrics having double, often personal meanings. When Kesey was a fugitive, Garcia had a relationship with another Prankster named George Walker who would become her husband in 1966. The marriage between Garcia and Walker did not last long and they separated in December 1966 and were divorced in 1978. She took up with Jerry Garcia after splitting with Walker, but they did not marry for many years after.