Premise: Yampa Valley Regional Airport (IATA: KHDN, ICAO: HDN) is in Routt County, Colorado, two miles southeast of Hayden and about 25 mi west of Steamboat Springs. Also known as Yampa Valley Regional Airport, it has the only scheduled passenger flights to northwest Colorado. It is also used by larger business jets that cannot use the smaller Steamboat Springs Airport (Bob Adams Field).
Hypothesis: Passenger flights do not go through Steamboat Springs Airport.