 Cook was hired as an engineer trainee, but went on to hold several management positions in labor relations, refining, marketing and planning, rising to become a Vice President of the company in 1970.After heading up ARCO's West Coast refining marketing operations, he chaired the eight-company Owners’ Committee building the Trans Alaska Pipeline System.When the multi-million dollar pump station burned, Cook proposed a solution of injecting a drag reducing agent to speed the flow, a success when implemented and resulting in the savings several hundreds of millions of dollars.