A Tweed Fly MUST HAVE!! The Junction Shrimp was named after the Junction Pool on the River Tweed. The River Tweed is one of the few Scottish salmon rivers where a degree of white has proved to be very successful. This may be attributed to the fact that the Tweed is an Autumn run river and come October and November the light draws to a close very early. The white in the wing of the Junction Shrimp and other white wing patterns make it a very good fly for making the best of the available light at dusk.