I just left COS for DEN. I was a junior lineholder in COS at just under 7 years seniority. The junior CA there is about 6 years. I should be able to hold a line in DEN, but am not 100% sure. Up until recently COS was more senior than DEN for Captains but recently it has taken about 7 years seniority to get into DEN and 6 to get into COS. With the opening of the PHX base both DEN and COS will go more junior. They haven't awarded the bids but looking at the list it looks like DEN will lose several Captains to PHX and also backfill into other bases out west (LAX, FAT, TUS, SLC).