There were 10 of us in a hunting party split up by twos; while waiting for sunup, as we had arrived prior to daylight, and knew where each group of two would be as we scouted the area days before; myself and buddy saw it first, thinking it to be an intruder on our hunting lease, 5000 acres of bare land but for sage brush. We thought it a truck coming down a small hill in front of us, as it showed the sage brush in its lights as a truck would; then suddenly, instantly it rose straight up in the air a few hundred yds and stopped, pulsating and glowing different colors of light; my buddy was too scared to speak to me as we watched it not knowing what to do if anything; this was something of unknown origin; and was seen by all other members of our 10 person group; two of the party saw it up close as it eventually hovered closely over them; about 200 ft by their account and said it was shaped and looked like a bus and had what looked like windows; no noise but the grass moved around them as it hovered.It's movements and color changes were nothing any physical known object could make, as it took off and stopped at speeds like the snap of a finger traveling great distances and back, up and down and then hovered slowly before moving off at great speed.I was in my 40s at the time and recall it as yesterday; the others admitted on the way back seeing this object just as the first two of us did; no one wanted to admit it till I brought it up while eating at a gas stop on the way home in Oklahoma.......an amazing event to have witnessed; later yrs there I asked a guide if there were ever such sites there by locals and he said indeed there were from time to time; NW Colorado is the location.