Half-tone print in the California Historical Society collection, sourced to Title Insurance and Trust and C.C. Pierce Photography Collection, 1860-1960. CHS card file entry reads:
"He was the father of Marie S. Lopez de Cummings and grandson of Claudio Lopez who came to mission San Gabriel as assistant to Father Salordio Juan. Lopez who arrived at San Diego on the same vessel remained there with Father Juan at the mission."
Claudio Lopez's brother was was the father of 1842 gold discoverer Francisco Lopez ... so the man in the photo was a cousin of the gold discoverer.
This photograph has often been wrongly identified as Francsico Lopez, the gold discoverer.
Chart by Tricia Lemon Putnam. Click to enlarge.