From Islapedia

FARRELL, John R. (1830- ), born in England, was a member of Stehman Forney’s Coast Survey party on Santa Cruz Island in June, 1875. Farrell was discharged in July, 1875, at which time Forney noted: “I regret very much having to part with him…” Farrell is listed in the 1875 San Francisco directory as a surveyor for the U.S. Coast Survey. He was chief clerk at the Arizona office of the surveyor general in 1878.