Originally Posted by Seat 2A
I did however once have a TSA agent deny me entry at the security checkpoint for NW and the South Satellite because my ticket was for travel on Alaska. I tried to explain that I could get over there anyway via the AS/NW Shuttle Bus at Gate C2 or I could take the connecter train from the North Satellite, so it wasn't like such access wasn't allowed. Fell on deaf ears. Not the brightest agent. In any event, if that happens, just go down to the North Satellite checkpoint and take the connecter train to the South Satellite station, then off to the South Satellite from there.
That must have been before all gates were connected BEHIND security. Now, you can go through any security checkpoint for any gate (in fact they sometimes suggest that you go to one of the less crowded checkpoints).