Beginning with Native American history, it is a common form of communication of the Sasquatch to scream. The following account is an example of such behavior, and is common among reports from the past 200 hundred years.
This account is an excerpt from a letter sent originally t John Green in the 1960's.This story comes from Oakville, Washington.
"The spring of 1933 was a wet one and also as I remember we had a lot of snow, All the ranches in our area were on the river. We all farmed the bottom land but built our homes on the hillside. This area had been logged by the Balch Logging Company in the period of 1915-1923. By 1933 a lot of the hill area had second growth timber on it. I was attending high school in Oakville at this time and this particular weekend I had been to a dance in Oakville with a group of other young girls.
When I returned home I always walked around the house to the back door. All my life I had hear coyotes and cougars. Just as I started to open the back door I heard a very loud noise up on the hill.
I had never heard a noise like it before and I was a little scared. I went in and woke up my mother and told her to come and listen as this was a noise I had never heard before. Also I could hear another one answer way over on another hill.
Mother got up and her reaction was so strange that could hardly believe it was my mother. She kept saying, "It's that terrible ape again."
When I kept trying to ask her to explain she kept saying I'll tell you tomorrow, and lets get inside as we are not safe out here. This is the story my mother told me the next day.
After my grandfather died my grandmother divided up the old ranch ad gave the children a Stump ranch. About 40 acres and most of my mothers land was the area where our house stood. The timber came down to almost to the back of the house. She said in the fall of 1912 my father had gone to Aberdeen to sell potatoes he had raised on the10 acres they had cleared. He had to stay all night so mother was alone in the small house.
The house had a porch across the front and a large bay window. She said she had not slept very soundly because she was not used to being alone. She said about 1:00 a.m. she heard a terrible stomping noise on the front porch. She got up to see what it was. It was moonlight outside, and at first she thought it was a bear on the porch, but this animal was standing on its back legs and was so large it was bending over to look in the window.
She said it appeared over 6 feet tall and it didn't look like a bear at all in the moonlight. She said in a few minutes it waked over and jumped off the front porch and started around the house. She went into the kitchen so she could get a good look and she said it looked just like an ape. She said the strange thing that had scared her most was the noise it made as it walked around the house.
She said as soon as it was daylight she went over to my grandmother's place and told them what she had seen. Her brothers all made fun of her and told her she had had a nightmare. When my father returned home he wouldn't believe her either. She said she would never mention it again. This was the first time I heard her tell the story.
The Sasquatch's screaming, then another returning the call from another ridge is commonly reported, I have heard this myself numerous times during field investigations. Why they do this? it could be to communicate food, be used for mating, or an alert to danger in the area they are currently feeding in.