An account in Skagit County, Washington

I was driving on the North Cascades Highway (HWY 20) traveling east across the pass. It was close to twilight and it was clear and cold. While close to Rainy Pass (maybe a bit before), I see something that strikes me as not normal. It is about 1/4 mile up the highway on the side of the road. At first, I think that it is a large man wearing dark, winter clothing. As I got closer, I see that it was clearly not a man. But just before I got a better look, it slipped down the side of the road into the ravine. And that was when I knew what I had just seen. The way it moved was sylph-like. Almost as if it shimmered away. I looked back to where it had been, and it had completely disappeared. Now, if that isn't enough for you, there's more. About two miles further up the mountain pass, I saw another. It was a little smaller, but moved in the same graceful manner as it quickly went down the side of the mountain out of my view. The leaves on the tree that it had been next to still gently shook as I drove by. I cannot say with any surety what these creatures looked like exactly. But they were definitely not bears - too tall and far too graceful. They were not human - too graceful and quick. They were both dark though. If they were at all reddish, I did not notice. They both seemed to be very dark brown. The smaller one darker than the bigger one. If I was to guess size, I would say the larger one was 6'4" - 6'8" and probably around 250 - 300 lean pounds. The smaller was perhaps 6'0? And around 200 lbs maybe? The thing that was so completely out of the ordinary, was the manner in which they moved. I have never seen something so large move so fluidly. Picture the way an otter or penguin moves in the water. It was sort of like that.