Untitled Sighting

Four of us were bowhunting in the Douglas Mountain area on private property.  It was around 3:00 PM and my brother was bugling for elk on a hill about 500 yards away from us.  Our younger sister was with him.  Our dad and I were sitting in our vehicle and our dad began to bugle at my brother.  The commotion got a response.  We heard an eerie howling ooooooeeeeeeeeuuu that was very powerful.  In a way it sounded like a human trying to sound like an elk.  The area we were in is miles from other roads and had no other hunters.  Neither one of us was making the noise.  Our dad got out of the truck as the sounds began to draw closer.  He saw a dark brown flash of fur in the pinions and cedars.  He thought it was an elk at first but knew the color was wrong.  We have hunted all our lives and knew the sound was not that of an elk.  When dad realized it wasn't an elk he became very nervous and jumped back in the truck.  When my brother and sister returned we asked them if they heard the same sounds and they said they did.  The closest sounds that resemble this are off the Bigfoot websites.  After the incident we quickly drove out of the area and we didn't return to hunt again.