Walking gsd 11:40pm. helena, mt on hill near st peters hosp fall 2013. clear sky. glanced at sky to note any familiar constellations noted a â€œstarâ€� seemed to be moving slowly to w at 35 deg above s horizon. thought it was a satellite. speed of object increased (more quickly than a conventional craft could do) still on same trajectory. object then dove rapidly at approx 30 degree slope from original line of flight, dropping to 30 or so degrees above horizon. without pause object increased velocity and climbed (swooped up) at 40 degrees from original flight path, toward the sw. object then leveled and swung in broad curve to w of city of helena where it quickly slowed, then stopped. what appeared to be a star in a line of sight that would have it appear near the object suddenly climbed rapidly at angle of 80 degrees, disappearing from sight to wsw. first object moved through level arc returning to s of city but at low altitude (500â€™-1000â€™) and approached over low mountains to the s at high speed. object became clearly visible, passing within a half a mile of my position. craft was triangular in shape, appearing to be between 900 to 1,000â€™ in length and 300 to 400â€™ across base (rear/aft/stern). side view was of a wedge, narrowest at front/bow (which was radiused) and highest at stern. there were no observable protrusions noted anywhere on external surfaces of craft. the top and bottom both overhung the vertical sides of the craft its full length. as craft passed, five opaque circles were noted on r side of craft on the vertical surface between the overhanging top and bottom edges. circle sizes all increased along the side, with the largest nearest the stern of craft. at back/stern three large circles of equal size (100â€™ in diameter as a guess) appeared to be equidistantly spaced across the verticle wall of craftâ€™s stern, which was also over hung by both top and bottom surfaces of craft. i canâ€™t recall if the area where the side walls and stern wall met the top and bottom surfaces were radiused or faired into the surfaces above and below them. all craft edges were radiused. surface appeared flat black and â€œgrainyâ€� in appearance. after noting the surface texture (i had expected something smoothly metallic) i recall thinking â€œson of a bitch, this thing is designed for both stealth and for hi speed operation in an atmosphere!Â€� the three circles across the stern were a very bright dark reddish orange color but quickly changed, fading to a duller orange, then a flat red, then a brown, then blank. change appeared related to diminishing velocity. as stern circles changed, the circles on the r side, starting at the bow, briefly glowed dark reddish orange (like stern circles had first been noted) sequentially down the side toward the stern. only one circle at a time was glowing that same color that i had associated with craft forward propulsion based on the color of the three circles on stern i had observed as it came past my location, which had all been the same color at any given second. the ones on the side â€œrippledâ€�, brightening and dimming sequentially. it took several of these cycles for me to see that the ripple coincided with increased forward velocity, but which appeared to quickly slow/lose momentum. it suddenly reminded me of watching crew boats years earlier at uofw where rowers would dig in and the boatâ€™s speed would go up; then it coasted a bit, then theyâ€™d use the oars again to maintain their headway. the craft was on a course toward the ne which would have it pass close to the helena airport, and i recall thinking weâ€™d know in the next couple of days if it was visible to radar or not, unless it was us military development. i also thought that it would, if it maintained its heading, pass close to or over the nuclear missle silo system in northern montana. btw, everything happened much faster than it sounds like. at this time, the craft appeared to â€œcrabâ€� sideways coming closer to my position while still pointing itâ€™s nose toward the ne. my gsd suddenly went to the side door without prompting, clearly wanting to go into the house. (i usually had to spend five minutes getting him to go in the house) at that same instant my mood shifted from excited to one of apprehension with a sense of unease. i also noted that i suddenly couldnâ€™t clearly recall some details of the event that i had thought were seared into the memory banks due to their uniqueness. to this day, trying to recall them invokes a sense of unease. when last observed the craft was continuing toward the ne and appeared to be returning to the course it had been on prior to â€œcrabbingâ€� sideways. iâ€™d be happy to try to sketch the craft if youâ€™re interested.