George Haas, on Clark Ashton Smith:
Klarkash-Ton's, too, was a Fortean mind, ever questing, never denying. He was intensely interested in the unexplained, the unknown. I remember our discussing The Books of Charles Fort that day 11 September 1953] and our discussion naturally turned to UFOs, the "flying saucers." Klarkash-Ton had seen one, had seen something, a year or two before. It was on a hot night and he had been lying outside on his sleeping bag, gazing upward into the depths of space. Suddenly he became aware of a large object, like an indistinct shadow, darker than the night, passing slowly above him, blotting out the stars..
LATE ADDITION: Apparently, Smith described the even in a letter to H.P. Lovecraft. The letter was dated 1933, but in it Clark said the sighting occurred four or five years previous.