Latitude 23.65, Longitude -103.63
This was, if I remember correctly, my second participation in another annual expedition with the Sociedad Astronómica Guadalajara, A.C in November 2003. I was still a little too amateur for the camping activities so I remember this place for two reasons: the first for the extreme cold I suffered in my poor cheap tent and that didn't let me sleep; and the second because I haven't seen darker and more impressive skies than the ones I've seen there.
Sierra de Órganos is a natural desert park where you can find a chain of impressive rock formations. Although it is a desert you can find a diversified fauna such as coyotes, hares, quails, white-tailed deer, etc.
Since it is a natural park, there are not many services except for some designated camping sites with some grills, therefore you should take all the necessary equipment including necessary amounts of drinking water and enough food for your stay. Take all precautions and also include first aid equipment including a formula against scorpion poison. Another thing to take into account is the extreme variation of temperature in the desert: in the morning the temperature reaches up to 34°C in the hottest months and in the evening down to -4°C so I recommend you to leave well prepared.
There is another problem (which I can't confirm) : given the increasing problem of crime in our country not many of my stargazers/astrophotopgraphers friends have wanted to do a second expedition since we would be very few members and the astronomical and photographic equipment we carry is expensive. I just want to clarify that personally I cannot say for sure and exactly what the conditions of this place are at present time.
The park is located approximately 30 km from "pueblo mágico" (magical town, a designation of our goverment) of Sombrerete, Zacatecas, which is one of the towns with much tradition and culture. Before arriving at the park it is mandatory to taste the food and get to know the town. But I don't talk about it, I'd better leave you a complete documentary.
Gentlemen, what can I say? I have seen no better sky to observe than the Sierra de Órganos. Because it is deserted, because of its location, because it is not near any village that is contaminated with artificial light, it makes this an excellent place with a darkness that I have not seen since. The horizon is excellent except for the rock formations; even so the quality of observation is not lost. I remember how the constellation of the Ursa Minor including Polaris could be seen clearly with the naked eye, and how many stars and planets began to be seen from the sunset. I would give this place an 11 on a scale of 10.