Bright Amber Light over the Tumacacori Mtns, near Tumacacori, AZ, Shape Shifting Back and Forth to a Large TriangleWent outside with the dogs, just after dusk, at 7:55 pm Arizona Time, or 19:55 (7:55 MST). Close to full moon was up in the East, about 2/3s of the way to Zenith. Winds calm (reported as 3.7 mph WNW at Tubac), some scattered clouds in the sky, good visibility. My viewpoint was 3 miles due E of the Tumacacori Mission in Southern Arizona. Immediately saw a bright, wide amber light in the sky at about 20 degrees South of true West from where I stood. It appeared to be right above the Tumacacori Mountains/Highlands in the Coronado National Forest about 6 miles away. It hung just over a broad flattish area in between two small crests, at about 5500 feet altitude, although I cannot rule out that it was further to the WSW. The object wasn't Venus because its size was too large and also too wide, too bright, and the wrong color. I have observed inexplicable big and bright amber lights and displays a few times here beginning exactly three years ago this September.As I watched, the bright amber light suddenly faded away, revealing two small dim white lights at the horizontal tips of the wide area, and a small red light somewhere in the center. About 10 seconds later, the bright amber light gradually started to return, and, as it returned, it looked like there were 3 spokes of amber light radiating out at 120 degrees from another from a common center, close to where that red light had been. This made the object resemble a triangle before it got so bright that I could not see any particular shape except one that was very bright but wider than tall. I estimate the object was at least 100 feet wide, based on the size of other features on the Tumacacoris (including a "dry" stone waterfall drop) with which I am very familiar. It remained brightly lit for about one minute, then faded out quickly again (saw the small white lights at the horizontal tips again before it disappeared). It then reappeared one more time just as! it had before, and repeated the sequence above. When it faded away once again, I could see two small red lights on it that then faded away quickly. I waited a minute or two to see if it would reappear, but it did not. Checked the time; it was 8:02 pm or 20:02 Arizona Time, so I viewed the object for about 5 or 6 minutes.I did not hear any unusual noise, just a little truck rumble from I-19 that runs past the Tumacacori Mission. I can readily hear airplanes or helicopters traveling in that area, as noise echoes in the Santa Cruz Valley between mountain ranges. Sometimes helicopters "hang" in place over the Highlands at night (due to smuggling route), but their lights flash, and they are up higher in the sky and nowhere near as big. I visually scanned the North 2/3s of the sky, and did not see any other lights or unusual phenomenon (couldn't see the extreme South of the sky from where I conventional aircraft.I grew up near a military airbase, have lived near flight patterns for three major airports, and have attended a few air shows with state of the art military aircraft. My Dad worked with rocket scientists in the 1950s-1970s, and those guys (with my Dad sometimes in tow) ran tests way out in the middle of nowhere, and this sure isn't far enough in the middle of nowhere.