Bowles started to work as gaffer in the early 1970s on projects such as the drama Pickup on 101 (1972), the action film Magnum Force (1973), the crime movie Thunderbolt and Lightfoot (1974), the action film The Eiger Sanction (1975), the television drama James Dean (1976), the comedy The Big Fix (1978, with second key grip Tom James), the romance 10 (1979), and the television western The Last Ride of the Dalton Gang (1979).