1-. my self and my friends where at a ranch in Potrero chico ,N.L,Mexico, i was stading by the side of a swimming pool and my buddies went in to the open field to take pics of the stars, they suddenly yield at me to come and see what they where looking at. 2-. one looking starlike started moving down in to the earth very close to the ground and it hovered above a tree and realased beams of light, green and white color. the hill shined and we could see the rocks , trees and bushed from a distance of 700 hundread feet. after that a second star like flew into the mountain, a vertical 870 m big wall, where there where no climbers at the moment and no stablished routes to climb on, this light sigzaged, a 3rd light appeard in the very summit of the mountain, it was in the very edge of the summit, the light hide just behind the summit edge, so we walked backwards to be able to see it, we took 2-3 steps back, then the light was hovering , again ,it hide again. we backed backwards again , and we repeated the same pattern like 100 feet till the light disappeared, seems like the light wanted us to back backwards to be able to see it.3-.i knew it was a UFO for sure.and we all knew it.since it not the first time we see UFOS in that place, this time there where several objects in the nightsky ,and it looked like they where waching the earth from their stationary points but still hovering.4.some lights flew around the mountain , realeased and flashed lights in to it, some other where in very hight altitude just hovering and relaesing green and white beans into the sky. some other just vanished instantly.5. i was exited and some of my friends where kind of scared but i managed tp calm them down. i had a power full head lamp and lighted the objets that where in the mountain and not too far from us, they lights seems to react to it by flashing their lights.6-. they hight altitude lights spent all night in the same spot ,hovering and releasing random light beams green and white colors. some light where orange and red. the observation took place all night till the dawn and the sunrise started.