Bertino began work for Walt Disney in 1935. Apart from his work on feature films, such as Pinocchio and Fantasia, Bertino also wrote for the Wonderful World of Disney, and helped create a number of attractions at Disneyland, including Mr. Toad's Wild Ride, Haunted Mansion, Country Bear Jamboree, and America Sings. Until his retirement in 1977, he worked as an assistant animator and storyman for Mintz Animation, Harmon-Ising Animation, Disney, UPA, Snowball Animation, Grantray-Lawrence Animation ...