This survey consisted in selecting potential sites for a large telescope (30m-50m) in the north of Chile. This was done by using Chilean Military Institute 1:250000 scale maps of the area in question. The criteria for selecting the mountains in this survey are described below.
The criteria were utilized to eliminate potencially undesireable mountains from the survey. The following steps were accomplished upon finding a likely candidate that complied with the criteria: The mountains name, height, long/lat coordinates were determined, followed by its distances and the direction towards major light sources including mines and cities, then distances and direction to other mountains nearby were registered as well as the distance and direction to the nearest accesible road. Any additional comments and oddities about the mountain were also taken into account.

Criteria

• A mountain located between Latitude 31° South and 20° South in Chile.
• Mountains that were located on any international border were not considered.
• Mountains that were located on charted lava flows from extinct volcanos were not considered.
• Mountains close to Lascar Volcano and other fumarolic volcanos were not considered.
• Mountains selected had to have an elevation between 2500 and 5500 meters, there were some exceptions when a mountain was by itself or looked promising and was close to this height limit.
• Even though no weather data played a role in the choice of site selection, from references in the ESO workshop on Site Testing for Future Large Telescopes, the final report of the VLT site selection working group, the ALMA site testing at Chajnantor, and meteorological information from La Silla, Paranal and Cerro Tololo observatories (see weather information) , the principal wind direction in Northern Chile was determined to be from the North and West, with small changes to the South during the winter months, therefore sites that had no close mountains (within 20km) to the North and West were possibilities, whereas those that did have mountains to the North and West were not considered.
• Mountains on ridge lines running North-South were not considered, due to possible turbulence being produced by the other mountains or increased wind speeds due to the venturi effect. There was only one major ridge running North-South and that was the cordillera de Domeyko. The Northern edge of this mountain range has the La Escondida mine in full view, halfway down it is the Altamira mine, if this cordillera was determined to be sticking up into the Westerly flow of air at high altitude(4000m - 5000m) them there might be some good sites. The mining activity would have to be taken into account, if this was a serious area for the new site.
• Mountains that had various neighboring mountains of similar height and were close together (within 20km) were not considered as a possible sites. This produces a problem mentioned in the ESO VLT studies and site selection of peaking, this where a lot of closely packed mountains of similiar height produce unpredictable and often strong turbulent wind conditions.
• Mountains that were too steep (30 degree slopes for instance) on all sides and had no access whatsoever were not selected.
• Mountains that were to close to major mining activity or large cities were generally not considered (within 50km direct line of sight) unless there was a good reason, such as no mountains around it.
• Mountains that have existing observatories and room to build more were considered as possible sites.
• In areas where there was more than one mountain that had similar characteristics, only one mountain was selected as a representative of the area, this did not happen frequently due to one of the criterion being, no groups of close mountains.
• In this survey no mountain was left out because the access by road or trail to it was to difficult or nonexistent, each mountain that was selected has a direction (N,S,NE, etc...) and a distance in kilometers to the nearest road. Some of the  mountains are in difficult to get to places and it might require four wheel drive vehicles or maybe more drastic measures to get to the mountain, such as mules and by foot.