Photograph of men working at the General Petroleum Corporation's refinery, ca.1940. Three men wearing soiled clothing and hard hats are visible at center working at a machine while two other men look on at left. Poles lead up to a metal roof at top, while various chains and pipes can be seen at right. A pipe can be seen in the extreme foreground propped against the concrete flooring, while a shrub-filled hill is visible in the right background. Photoprint reads: "Derrick Floor: Hayes & Sprague crew. L. to R. -- L.D. Jackson (pusher), R. H. Colleman (correct), driller, J. D. Ester, W. D. Lacker, P. F. Breig" and "Derrick Floor -- Camulos Ranch #1 -- excavation(?) Piru Area".