it is in south Yorkshire visit
http://en.wikipedia.org/wiki/River_Don,_South_Yorkshire to find out more just copy and paste.
here is a picture hope this helps!
There are 3 River Dons in England. River Don, Lancashire, England River Don, South Yorkshire, England River Don, Tyne and Wear, England
The River Don flows for 70 miles (112 km) through the Don Valley in Yorkshire.
The river Don
The river Dee and the river Don both run through Aberdeen.
Beaulieu River is a river in the county Hampshire, England. River Bride is a river in Dorset, England. River Brue is a river in Somerset, England.
Don RiverHumber River
Voga-Don Canal. It runs between Volga River and Don River
The Caldew is a river in England. The Calder is a river in West Yorkshire, England.
The River Don.
River Dee River Don River Deveron
The sea which the Don River flows into is the Sea of Azov. This river is 1,212 miles long and is located in the country of Russia.
South Yorkshire - main conurbations are Sheffield and Doncaster