Mysterious flight over Colorado in 1955

Summary

In May 1955, a commercial pilot with American Air Lines spotted an unidentified object at 20,000 feet over the Sangre de Cristo range in Colorado. The aircraft left no vapor trails or distinctive features that could help identify its type. Despite the pilot's experience, cloudy conditions limited visibility. Due to the lack of clear information, no further investigation was authorized. The conclusion was that the object was likely an unrecognized aircraft, although other possibilities like balloons or astronomical phenomena were not ruled out.