The first thing that I would recommend is really researching the organization. DCPA is an umbrella organization that covers a couple of producing arms. One is Denver Center Attractions, which primarily handles tours but does occasionally produce shows (typically long running like Always, Patsy Cline shows like that), the other is the Denver Center Theatre Company, which is a LORT theatre with 4 spaces that are used in their rep season. One big difference is DCA is geared more towards commercial work and DCTC produces a mixture of classics, new work, and some old standbys, primarily plays.
The AEA stage managers who are at DCTC have been there for quite some time, but many of us who worked as ASM's have gone on to other great work. Most of us have gone on to working in other regional theatres or a similar level. As a side note, I learned almost everything I know about stage management from the SM's here. They are incredibly talented and have a huge amount of experience, and have been willing to share that knowledge with interns and ASM's as they come through.
DCTC has a great internship program, and is worth looking into if you are really interested in working there. It is a lot of work for little or no money, but the experience and on the job training you get are priceless.
SSM :-)