Hartsfield–Jackson Atlanta International Airport now the airport's second largest carrier. In May 2001 construction of an over fifth runway (10–28) began. It was completed at a cost of $1.28 billion and opened on May 27, 2006. It bridges Interstate 285 (the Perimeter) on the airport's south side, making Hartsfield–Jackson the nation's only civil airport to have a runway above an interstate (although Runway 17R/35L at Stapleton International Airport in Denver, Colorado crossed Interstate 70 until that airport closed in 1995). The massive project, which involved putting fill dirt eleven stories high in some places, destroyed some surrounding neighborhoods and dramatically changed the scenery of
Stapleton International Airport Denver to El Paso, St. Louis and Tulsa. Frontier operated northbound and southbound from Denver to the other mountain states. Western connected Denver to Minneapolis and Edmonton. The April 1957 OAG shows 38 United, 12 Continental, seven Braniff, seven Frontier, seven Western, five TWA and one Central. The jet age arrived in May 1959 when Continental began operating Boeing 707 jetliners into Stapleton, initially under weight restrictions due to Stapleton's runway capacity. Runway 17/35 and a new terminal building opened in 1964. Although Stapleton officially adopted the "International" name in 1964, its first nonstop international service came in 1968, when