Several companions of Isaac Graham, from his days as a fur trapper, also ended up in Santa Cruz. Joseph L. Majors seems to have been the first. By marrying the daughter of a Castro, Majors was able to obtain Mexican citizenship. That allowed him to own land including Rancho Zayante, which he then rented to various Americans, including Job Dye, Isaac Graham and Henry Naile.
Also, discovered a biography called The Trials of Isaac Graham, which is available at the UCSC library.