The San Luis Valley makes more sense as a trip than a checklist.
The darkness belongs to the whole region. The fun is seeing how many different kinds of night can fit underneath it.
Start big at Great Sand Dunes
Great Sand Dunes is the obvious anchor because the landscape is already doing half the work. A ranger program gives the night structure, but even without one, walking into a giant field of sand after sunset feels completely different from standing in a normal parking lot and looking up.
On a moonless night, the dunes can disappear into silhouette. Under a bright Moon, they come back as the main subject.
Same place. Different sky. Different night.
Then change the experience completely
Valley View Hot Springs puts you in the dark without asking you to stand beside a car. The UFO Watchtower leans into the valley's roadside weirdness and gives the trip a completely different personality.
Neither needs to imitate a national-park astronomy program. That is the point.
Keep an eye on what is developing
UNM-Taos sits just across the border and is worth watching as its public astronomy project grows. Treat it as a developing stop until the current public schedule is clear, then use it as an optional southern extension rather than a promise.
Leave an empty night in the itinerary
A strong valley trip might include a ranger program, hot springs, a roadside stop, a telescope and one night with no program at all.
That last night matters. Find a legal dark place, let your eyes adjust and watch the sky move for a while.
The variety is what makes the valley worth staying for.