Any ideas on this one?
Diverted from Denver to Colorado Springs after a little detour?
http://flightaware.com/live/flight/UAL342/history/20100702/1822Z/KSAN/KDEN
Weather. See the red spot on the route map, a little way out on I-70 east of Denver? That must have been close to DEN at landing time. DEN is just a little NW of there.
They often have to land planes in COS for an hour, maybe put an extra $5 in the tanks, and wait for clear weather; they depart COS straight into the arrivals at DEN. On a bad day they might get 6-10 a/c stacked up in COS.