Original oil and gas trade vintage ad for CLEAR SPAN ENGINEERING. COMPANY, INC. Main office was located at 1108 Prudential Building, Houston, TX. Revolutionary Oil Pipe Line Bridge used on the Yellowstone Pipeline in Montana and Wyoming. You can span the Mississippi with an insured, guaranteed, maintained bridge. Affiliated with Clear Span Bridge & Barge Company, of Houston, TX. This unique 1955 oilfield pipe line bridge construction magazine advertisement would display beautifully matted and framed.