Watchtree Nature reserve is situated on the Solway Plain, about 6 miles due west of Carlisle and 6 miles north east of the market town of Wigton. The nearest village is Great Orton, about one and a half miles to the west; the hamlet of Wiggonby, half a mile to the south and villages of Kirkbampton and Thurstonfield, about 2 miles to the north. It is situated mainly within the Allerdale District Council, with a small area falling into Carlisle District Council. It lies mostly within the Parish of Aikton, with smaller areas in Great Orton and Kirkbampton Parishes.