I have no current advice as my attendance there was when I lived north of Denver in the early 80’s. You will not be sorry you made the effort, it should be on all music fans bucket list to see a concert there. It’s a special experience. When I was going, it was all general admission, the earlier you went, the better seats you got. We’d go early if a show was on a Saturday. I remember going to the Doobies Brothers and being there all day. We were like lobsters by the evening, the it started pouring rain. But it was a quick shower and, as they say, the band played on. First show there was George Thorogood and the Destroyers (who I saw about 6 weeks later in Boulder when he opened for The Rolling Stones at Folsom Field). The view of the city lights after dark is really good from there. I hope you have a good experience.