During an evening outdoor event at a retreat center in the mountains, on of 14 witnesses drew out attention to a couple of bright lights off to the south west of where we were standing in a field. We all turned to look and noticed the lights slowly moving toward us. Suddenly, we saw a search light emit from the overhead light source and it appeared to be sweeping down on the tree tops. As the two lights got closer we could see they were actually 4 bright lights and a central less dim light blinking on and off. At this point we could make out a dark shadowy shape connecting the outer four lights, two on either end. This craft was making no audible noise (a windless night) and approaching almost in our path heading south east. I estimate the craft to be at about 1500 feet above us. As it was almost directly overhead, we could make out a faint constant engine noise. It was a cloudless night and the dark craft appeared to have no standard aircraft body, but appe! ar to be sort of winged shaped. I estimate the length from one to end to the other be about 200-300 feet. Its speed was similar to the speed and approach of an airline jet approaching an airport, however there is no close airports. There were no red or green navigation lights visible. The craft continued on its straight path until leaving our view over a nearby mountain.