The number of overseas passengers flying through Hilo peaked at 313,428 in 1971 and remained between 250,000 and 300,000 for most of the decade. According to the Official Airline Guide (OAG), in 1975 Northwest, United and Western were continuing to serve Hilo. At this time, Northwest was flying nonstop Boeing 747 service once a week from Portland (PDX) with this flight originating in Seattle (SEA), United was operating daily Boeing 747 service nonstop from Los Angeles (LAX) as well as nonstop Douglas DC-8 flights from San Francisco (SFO) five days a week while Western was flying Boeing 720B service nonstop from Los Angeles (LAX) twice a week. A year later in 1976, Continental was once again serving Hilo with a daily direct McDonnell Douglas DC-10 flight from Denver (DEN) and Los Angeles (LAX) with this service making an intermediate stop in Honolulu while at this same time United was operating a Douglas DC-8 flight four days a week with a westbound routing of New York Newark Airport (EWR) - Cleveland (CLE) - San Francisco (SFO) - Hilo (ITO) in addition to operating daily nonstop Boeing 747 service from Los Angeles (LAX).