I do agree with the above two posters, but wanted to say that the Montessori program I mentioned is authentic. I worked there for 3 years, and most of the teachers are AMI trained, with the rest being AMS trained. It's also a bilingual program, as each room has at least one staff member who is Spanish speaking and another who is English speaking. It's pretty cool.

But it's true that anyone can use the name Montessori or waldorf, and there
are also wonderful programs not affiliated with any label you should consider. It just takes some time to go tour, observe in classrooms, talk to parents, and get a good feel. The problem with Denver is that the most sought after schools/daycares often have waiting lists and/or are hard to get into (many use lottery systems). It might be necessary to start out at one place, even if it's not your first choice, and work on getting into another. Still not sure what part of Denver-metro you live in, or how far you are willing to drive, but I could recommend other schools as well.