Scott, in Colorado, it is a good chance that you may be able to get by without a moisture trap due to the usually low humindity. However, it also depends on how hot your compressor gets. If it is hot to the touch after 15-20 running continuously, it is a good insurance policy to get a moisture trap.

It is summer time now. Run a long airbrush session of 30 minutes or more. If you do not get water drops in your paint at the end, you are alright as is.

At the very least I would put a trap on my A/B like the one that Iwata sells. Kobalt makes a trap and regulator in one, so you may be able to take the regulator back and get the one with the trap. It does no harm and may save you the heartache of having water spurtting from your AB.