95% of the time I use a 9' 4wt in the mountains, and yes, even on small streams. If it is really small, with overhanging brush, I use a 7' 3wt. I like to use a long rod and keep line off of the water. I also like to high stick nymph, so the longer rod really comes in hand.
Many go fishing all of their lives without knowing that it is not fish they are after.
- Henry David Thoreau