Complex sentence: The three of them went on a trip to the Rockies, returning to LA by Frank Sinatra's jet: We left Denver in Frank Sinatra's Lear Jet, which he very kindly loaned us.
Split into simpler sentences: The three of them went on a trip to the Rockies, returning to LA in Frank Sinatra's jet. Evans: We left Denver in Frank Sinatra's Lear Jet, which he very kindly loaned us.