On a girl's four day high Sierra hiking trip - staying at May Lake camp in Yosemite, close to 9400 ft. Went out to the ridge to lie down and star gaze around 9:15 pm - half moon so not totally dark. Noticed numerous jets overhead - saw the satellite pass by and then I noticed a star move just a bit. I thought the light from the moon was making me see things so I covered the moon light with a hand cupped over one side of my face to watch the star again. It was within a small cloud hole so I had reference to the movement and it was definitely moving. I got excited and told the gal next to me to watch it - she saw it move as well then we continued to watch it and it started moving more and this time erratically, going up and stopping then diagonally then stopping, down and stopping - it was completely bizarre and definitely up in the stars, not low like a laser - it was white like a star, didn't blink - it continued it's strange movement until it shot straight up and stopped then I was super excited and was trying to show the third gal where it was when I lost sight of it. We watched it for a good ten minutes. I'm curious if anyone else noticed the movement on that night since it was happening for a good ten minutes.