The Great Sand Dunes is apparently listed at the 8th best national park to start gaze, but that is way far south west. I googled up Dark Sky Havens in Colorado and found this article. It's a little old and a couple of more places have been added.
https://denver.cbslocal.com/2020/10/07/colorado-international-dark-sky-locations-places-to-visit/
In the end, get away from the I-25 corridor to someplace in the mountains or the plains and the star gazing is pretty spectacular.