Small town travel assignment in Colorado or N. Cali

I'll be starting travel nursing next June with my wife and 6 yr. old son coming along. We live in Central Florida and can't wait to get out of here.

Tentatively, our plans are to start somewhere in Colorado or Northern California. We know nothing about either state, but we do know we want no large city or alot of people. I'm just looking for suggestions or idea on where to start planning on researching.

Anyone got any ideas, suggestions, or recommendations that might fit what i'm looking for? Somewhere small and quiet (relatively speaking) that is good for travelers.

Also, any advice on when to start contacting agencies if we look to travel in June?