On April 19, 1978, police officer Mark Coltrane was on patrol in the vicinity of Colfax, a small town with a thousands of inhabitants in Wisconsin, USA. At midday, he decided to stop the car to eat something, in a small isolated area. He noted that his radio was emitting crackles.

He then noticed a metalic looking disc raising towards the the sky at a short distance from the parking space.

While the object seemed to move towards him, Coltrane picked up his Polaroid camera, came out of the car and snapped some photographs. The object was so close in one of the images that it is possible to notice some details of its lower surface.

The total observation lasted a few minutes, the object being being lost from his sight when it accelerated and fled in the distance.

Coltrane, shocked by the sighting, remained in amazement for two hours without saying anything, by fear of being ridiculed when he would have to submit his report to his chiefs.