<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by dldkjones:
if I need to exit and re-enter through security to check in on the other airline, I may not have enough time. Can I check in for the return flights at the departure city? </font>
Where are you connecting and changing metal? In most if not all hub cities, NW & CO share terminal buildings. You may not need to worry about security.