A native of Pennsylvania, Mitchell traveled West for the first time during the Gold Rush while still a teenager. After prospecting in Nevada, he continued on to California. He began studies at the San Diego Academy of Art in 1913 where he studied under Maurice Braun. He furthered his studies at the Pennsylvania Academy of Fine Art where he studied under Daniel Garber and Joseph Pearson.

In the early 1920s Mitchell returned to Southern California and served as President of the San Diego Art Guild in 1922-23. He was a founding member of the Laguna Beach Art Association and the La Jolla Art Association.