We had reserved some class 3-4 rafting near Denali.

I asked the guide what class this one was, and he said it was a class 4. I told him it didn't look like a class 4, and he said the temperature of the water is a contributing factor. The fact that if you go in the water, you only have a few minutes before hypothermia hits apparently makes them more serious than warm water rapids.

Before.

After.

Brrrrrrrrr!