Western Airlines was the first carrier to serve Casper tracing its roots back to 1931 as Wyoming Air Service with a north-south route from Denver to Great Falls, Montana stopping in Cheyenne, Casper, Sheridan, Billings, and Lewiston. Wyoming Air Service changed to Inland Air Lines in 1938 and was merged into Western Airlines in 1952. A new east-west route was then added from Salt Lake City to Minneapolis stopping in Casper, then at Rapid City, Pierre, and Sioux Falls, South Dakota and the north-south route was extended onto Lethbridge and Calgary, Alberta, Canada. Aircraft types operated by Wyoming Air Service and Western over the years included Boeing 247, Douglas DC-3, Convair 240 and Douglas DC-6B propliners, and Lockheed L-188 Electra turboprops. By 1970 the carrier began operating Boeing 737-200 jetliners on both routes, still making all the stops however the north-south route then terminated at Billings. The north-south route ended in 1979 and the eastern portion of the east-west route extending into Minneapolis ended by 1983, leaving only flights to Salt Lake City and Rapid City. Larger Boeing 727-200 jets were occasionally flown through Casper and in 1987 Western was merged into Delta Air Lines. Delta continued service into Casper with nonstop flights to its Salt Lake City (SLC) hub as well as Rapid City until 1994 when all operations were turned over to SkyWest Airlines operating as the Delta Connection using Embraer 120 turboprops. SkyWest continues to serve Casper today with nonstops to Salt Lake City using Canadair CRJ-200 regional jets.