Ten or more orange fireballs moving southerly along the east edge of Billings, MT.On June 2, 2012, approximately 9:45pm mountain time, I was summoned outside by my brother. I exited the house, and looked east, where my brother was pointing at something in the sky. Three orange fireballs were clearly visible moving in what appeared to be a southern trajectory, although it may have been southeast or southwest. The lights would have been near the eastern city limits of Billings Heights. As we watched the first three crossing the sky, more continued to come into view, as several large trees blocked part of the sky from our sight. I counted at least ten. Most of them seemed to be moving in a line with each other, althrough three of them formed an irregular triangle formation. At one point two of the orbs came close enough to eachother that they appeared to touch, before swirling around eachother for a moment. The lights all made their way across the sky, eventually fading into some cloud cover. The entire incident lasted less than 5 minutes.The lights would best be described as orange fireballs. Their size was quite a bit larger than any star or planet would appear, and they were clearly visible even though night had not quite fallen and the sky was still fairly well lit. There only appeared to be the singular orange source of light for each light. There were no additional or blinking lights that might suggest an airplane or helicopter. They appeared to be flying lower than most airplanes would fly.