I looked up Jackson, Wyoming. You are totally surrounded by mountains. Yes, while the winds may change, these may be to your benefit with keeping things dry - moving air does not form dew.
My own Club goes up to the mountains immediately west of Sydney, not just for the darker skies, but to take advantage of the better astro conditions that they provide. Of course, like every place, being able to use any location for astro depends on the weather of the day, but this is where you need to know & understand the conditions of the whole landscape, not just settle on one model that means you exclude a particular location based on preconceived ideas, urban myths and also misinformation. For that reason while our preferred location is up in the mountains, weather may have the mountains clouded out but the Sydney basin may be clear, so we need to be flexible and open minded on what areas we do have access to so we can take advantage of where the clear sky is, even if this may mean a less transparent sky or one with more light pollution.
That there are mountains, and valleys, is good. It means that on nights of little wind, air will flow down off the mountains into the valley below, creating laminar airflow on the ridgetops - EXACTLY what you want for good seeing. This light breeze flowing down into the valley will be enough to help keep your gear dry all night long. The site my Club used for 16 years, we had dew from on only 8 occasions and of these only 3 times was it heavy enough to impact on our optics. The vast majority of nights we packed up bone dry gear or at worst with only light dew to deal with. Knowing now that dew and astro are not inseparable bedfellows means I won't go to places that I know will drench my gear.
Transparency will also always be far superior up high than in a valley.
There is also the microclimate aspect that no weather app will show. Again with my Club's site, its geography, geology and land use meant it was most often totally clear of cloud and dry while just 2km away the area was fogged out and soaking wet! And we had no idea about this until we had packed up and were on our way home. Our site was on top of a sandstone plateau that had no agricultural land on it, only dry eucalypt forest and it was an airfield with a earth runway, not turf so it drained very well.
As it was an airfield it was very exposed to any wind. However, it was lined with tall trees that offered protection and on nights when wind was difficult, we just needed to shift from our preferred spot to one that provided more shelter from the wind.
We are also very familiar with the seasonal weather patterns and always monitor daily conditions. We often saw thunderstorms crash and smash the early evening, but we knew that in two hours time these would not only clear but the sky would be just spectacular. We know that when there is a strong easterly wind blowing in from the coast the mountains would be a no-go for us as this moisture rich coastal wind would create clouds as it pushed up over the mountains. We know this area very intimately.
It took us years to work out the microclimate aspect that ultimately directed us to the Airfield we ended up using, but we started from zero. You however, are starting from a far better position, being made aware of things to look out for that we had to slowly come to recognise.
To further encourage you, my Club spent a long time looking for an even darker site to hold our Astro Camps (our Club's home site was Bortle 4, our Astro Camp site is Bortle 1). In looking for this camp site we took everything we learned from our experience with the Airfield and applied it to this search. For instance all formal camp grounds are NOT set up with astro in mind, so these will be 99% of the time in a valley or with a microclimate that is astro-crap. Areas that are good for astro will often be poor with facilities. It took us a year, but we found the best possible combination of a good astro site with outstanding facilities, and it isn't where most people would consider an astro site. But we are not most people...
Poor over topo maps (Google Maps is great for this). Go for a visit to prospective sites. Ask the locals - airfields are great sources of info as it should be no surprise that pilots prefer to fly through the exact same conditions that give us great seeing, AND they really know the local weather patterns like no one else. Other locals may either have a paddock they may be happy to offer you to set up on or may know of someone.
The pic below shows what I mean about setting up in a valley as being a poor option. You really want to be up high.
Alex.
