Untitled Sighting

On 6-94 we visited Yellowstone National Park and rented a cabin near Teton Lake. My wife and two sons were with me. We left one morning just after dawn to visit the Grand Canyon of the Yellowstone and see the sights. A short ways up the road I looked to the right and there was a big open flat field with a body of water running through it about nine foot wide. Tall green grass about waist high was growing --it was a beautiful sight. About sixty yards out or so I saw a tall, dark, hairy figure standing close to the water. It stood seven foot or so tall with it's back to us and it's head turned to the left. Its features were massive and very powerful. It was no bear because it heard our van and saw us and took off walking like a man. Its stride was long with it's arms swinging as it walked. My entire family all saw exactly the same thing. The light visibility was quite good. I told all family members to keep their eyes on this creature and to look at nothing else. We finally drove our car through some trees on the road and could no longer see the creature.