UFO sighted by military patrol in Kentucky

Summary

A 1965 report describes a UFO observed by a military patrol at Fort Knox, Kentucky. The object was seen ascending in a spiral until it disappeared from view. Witnesses estimated it to be about 50 feet in diameter and moving in circular patterns. Despite a 20-minute observation and favorable weather conditions, no photos were taken and no physical evidence was found. Investigators concluded it was a balloon, though the witnesses insisted the behavior was atypical.