I'm not sure about the Denver theatres' pay, but I assume that you're talking about all non-union houses here. In that case, you might expect far lower pay than you're suggesting. Most gigs will pay you a flat rate, not an hourly rate. As you discovered, you'll see hourly rates for things like professional tours, which also happen to pay pretty well as far as gigs go. If you're being paid a flat rate, you'll get paid at the end of the run, so you won't have any cash flow through rehearsals - plan for this!
At many small community theatres, you might not get paid at all, but you'll get experience and networking opportunities. (This is how most of us start!) At small semi-professional theatres, you could expect anything from $200-$500 per production - and this includes rehearsals and all performances. This rate can vary quite a lot depending on the theatre's budget. More established theatres (with larger budgets) could pay significantly more per show, but still you will probably get a flat fee per production, not an hourly rate, and again the rate will vary a lot. Opera tends to pay well (and has a shorter rehearsal period), so you should definitely look into Central City Opera and Opera Colorado if you can read music.
I hope this somewhat basic answer is a bit helpful to you! Perhaps some SMs more familiar with the going rates in the Denver area will chime in with tips...