Phyllis , You're right. San Joaquin Valley is here in CA--the central part--and a Mexican explorer named it after Saint Joaquin (or Joachim , in English). Saint Joaquin is an important saint to Roman Catholics, especially in Mexico and some of the other Central American countries, b/c he is the father of the Virgin Mary--I know there are several villages in Mexico that have adopted him as their patron saint.
Nanaea , I wondered why Joaquin was a "hippie" name, too, but your theory sounds right to me. San Joaquin Valley is a huge agricultuural community, and it's not really too far from the San Francisco area. Whoever put that website together might also be referring to JoaquinPhoenix , whose parents were hippies themselves? Either way, it's a cool name--if my daughter had been a boy it would have been his middle name:)!