Alaskan North Slope natural gas pipeline route alternatives : a Port of Seattle analysis / Alaskan North Slope natural gas pipeline routing alternatives : a Port of Seattle analysis Port of Seattle. Seattle City Documents. Natural gas pipelines Pipelines Pipelines Pipelines 388 THE 1997 C147 Or. "April 22, 1977." [Seattle, Wash.] : [The Port], [1977] [1977] Text viii, 157 leaves. :