Untitled Sighting

Well this happened twice in our area, which is on the navajo reservation in the northeast corner of Arizona. Mid winter in 1979 myself and other neighborhood kids were playing in a recently fallen snow, and out of the darkness  was heard the most terribly and interesting scream that we've ever heard and this scream lasted for about 15 minutes on and off. Now at the time I remember their being reports of a giant Yei Men taking sheep from corals, but I didn't believe until that night. The time must have been about 12 pm.  What is ironic about this incedent is that it did not only happen once but twice three years later in the same conditions. And, their were low key rumors at the time. Now this hasn't bothered me but I sure would like to know how it ever wandered into our region for a fact. In our oral history our elders spoke of  Yei Men of  whom will come and take you away if your bad. I mean just put two and two together?  Now this had to be a Bigfoot, because on several recordings, the sounds are identical to what we heard that night!  And, even on an episode of sightings the night cry was identical. This just gives me the creeps, to know that at that time we were probably  being watched.