The Dean Heritage Museum Trust was founded as an educational trust in 1981, with the aim of setting up a museum to conserve what remained of the unique history of the Forest of Dean and its people. This was followed by the collection of historical objects, travelling exhibitions and the formation of the charity. The Camp Mill site was acquired and with the help of the Community programme, local government and local businesses the Museum opened in 1983.
The Gage Library contains the Museum's collection of books maps and archives on the Forest of Dean. It houses a major bequest from Laurie Gage, an antiquarian book dealer with a great personal interest in the area. Millgrove Wood, a small woodland of ancient earthworks which is adjacent to the Norman Littledean camp were also donated to the charity in 1987 by Cyril Hart.