Ches Whitley was a Human male living in the late 19th century.

He was an acquaintance of Samuel Clemens and an employee in the County Assayer's Office in San Francisco on Earth in 1893. He informed Clemens that Data had visited his office several times, seeking information on mining operations in the 1850s. (TNG: "Time's Arrow, Part II")

This character was only mentioned in dialogue.