The Devonshire River is a river located in the south-west of England. It is formed by the confluence of two rivers, the Exe and the Tamar. The Exe is a river in Devon, England, that rises near the village of Exford and flows for 60 miles before joining the Tamar at Exeter. The Tamar is a river in south-west England that rises on Dartmoor in Devon and flows for 50 miles before joining the Exe at Exeter. Together, the Exe and the Tamar form the Devonshire River.