Saw something that moved too fast to be either a plane or a satellite and made an impossible right turn then vanished.

I was on a trip with my youth group at Cultus Lake and was sitting on the beach at approximately 11:30 with my friend, talking and looking at the stars.  It was a mostly-clear night, if memory serves.
I was looking across the lake at the sky above Vedder Mountain and saw a shape that looked like a satellite, moving up and left from my point of view.  At first, I thought is was a satellite, or even a fighter jet. But it was moving WAY to fast to be both.  Suddenly, it made a sharp turn, to the right, too sharp for a jet or satellite, and disappeared.  The magnitude was about the same as that of a distant plane/very bright star.
I don't know what I saw, but it was definitely odd. And I've seen satellites move, and they do not move like this. Or any type of plane.  My friend did not see the object, but was just as confused as I was when I told her after the object disappeared.