The river Avon in Bristol south west of England is 75 miles long.
it's about 35 miles long and has 14 beats open to visiting anglers. (Source, http://www.riverannan.co.uk/)
The Bristol river Avon is about 75 miles long
There is no "minimum length" to be classified as a river. However, width, and to a lesser extent depth do figure into whether or not it is called a river. If one can toss a rock across it, and it is...
Principal Scottish rivers include the Tay; Clyde; Forth; Spey;Dee.