6 October 1967
(The Lewiston Daily Sun, Lewiston-Auburn, Maine)
http://news.google.com/newspapers?id=v8k0AAAAIBAJ&sjid=JGkFAAAAIBAJ&pg=820,4394157
The incident occurred near Alamosa, South Central Colorado (San Luis Valley) in early September 1967.
Quote from the article:
“Did Snippy, the horse come out second best in a tangle with a flying saucer?
Mr. and Mrs. Berle Lewis, owners of the 3-year-old Appaloosa, whose mutilated – and reportedly radioactive – carcass was found in a remote area of Southern Colorado’s San Luis Valley, declare firmly that’s what happened.”
Wkipedia article: “Cattle Mutilation (The Snippy (Lady) mutilation)”:
http://en.wikipedia.org/wiki/Cattle_mutilation#The_Lady.2FSnippy_mutilation
Map of Colorado
(yellowmaps.com image)