"Southwest Airlines will begin nonstop service to Denver on September 6 instead of in December as earlier planned.  Southwest will also suspend service to Las Vegas and Phoenix temporarily.  Passengers will be able to access Las Vegas and Phoenix on Southwest through Denver.  Southwest plans to return the Phoenix service in January and Las Vegas in March." 
Full details here: https://www.flywichita.com/southwest-airlines-to-begin-denver-nonstop-in-september/