The San Luis Valley made the strongest case so far for treating the trail as a trip rather than a checklist.
Great Sand Dunes
The ranger program I experienced was short but good. The park gives visitors a legitimate dark-sky anchor, but it is only one piece of the valley.
Valley View and the UFO Watchtower
Valley View Hot Springs was an excellent experience, while the UFO Watchtower is unique in a completely different way. Neither needs to imitate a national-park astronomy program to belong in a useful night-sky itinerary.
The projects still developing
UNM-Taos is just across the border and is worth watching because of its major public-telescope ambitions. I have not attended a program there, so I list it as promising rather than reviewed. The same principle applies to new lodging and astronomy concepts: a future plan should never be written as if it is a current guest experience.
What I would tell a traveler
Stay longer. Use the official trail as the spine, then explore the valley around it. The darkness is a regional asset, and the best trip may combine a ranger program, an unusual roadside stop, hot springs and a completely unprogrammed hour under the sky.