While investigating a case of an encounter, i came across a few newspaper articles about cattle mutilations in teller county colorado. i believe i was able to get the entire string from june 1975 to june 1976. these mutilations centered around a small area called gillett, colorado. the interesting part is that on september 18, 1975 there was a mention of helicopters being photographed in the area that matched witness accounts. also on the gillett wikipedia page there is a mention of unmarked helicopters. i contacted the teller county sheriff's department, unfortunately their records don't go back that far.