Setting flag for drop-down choice

We have a drop-down list of states, which fall into two categories - participating and non-participating.  I would like to find a way to flag each of these states so that I can write triggers and conditional field viewing based on whether the state is participating or not.  Currently all of these are set per state - i.e. the trigger has "if state is x then send participating email" or "if state is x show this field" but that requires changing all of the triggers each time a state joins or drops out.  I want a way to set a flag so that the trigger could be "if flag is participating then send participating email" or "of flag is participating show field".  I can write one trigger that has "if state is x then participating is true" then use that with the other triggers, but that doesn't help with displaying conditional fields because it isn't dynamic.  Has anyone done something like this?  Any suggestions?