As previously stated in this thread I am a long time Fly Fisherman and have fished both Ft. Lewis area and Okinawa. Keep in mind I was just a little kid but I have been lugging fly rods around the world since I was 8.
If you are heading to Okinawa I suggest you start looking in to tenkara -
http://www.tenkarausa.com/ There are many small streams and plenty of fish on the island but also a lot of snakes.
I focused mostly of carp.
In and around Lewis there are a few great lakes and several nice rivers. When we were at Lewis I lived right on Sears Lake which was restricted to 16 and under. Other than opening day I pretty much had the lake to myself all year.
I now live in Boone NC so if any members want to wet a line in the mountains of NC let me know. If I can't go with you I can sure point you in a good direction.