In a small area, only about 400 meters in diameter a lot of the farmers in the small villages Handbacken and Forsen in Björbo, harvested their peat at least from about 1900 until 1950'. When the cattle dissapered, no more peat was needed either. About 1970 a documentation of the area was done. Eighteen barns and simple roofs for peat storing was still present at that time, and by interviews with old people, it was documented which barn belonged to which farm. Today (2005) seven ruins of timber barns and one board barn remains.
The cross jointed timber barns are in most cases old hay barns moved out at the bog. Samples from the remaining timber have been dated by Torbjörn Axelson. The youngest annual rings was found to be from PM02: 1764, PM03: 1799, PM04: 1759, PM05: around 1805, PM06: 1731. Three of them are probably build as peat barns already from the beginning (PM13, PM14, PM16). Unfortunately they are all build of fire damaged spruce timber, wich contains only 30-45 annual rings, i.e too few for a dendrochronological analysis. The last barn, PM17, was build by boards on a construction of pine logs taken from the bog, dated to the summer 1931.
Before the peat could be stored in a barn, it had to dry on a drying-hurdle during the summer. Most of those hurdles are totally rotten down, but the parts below peat surface are indeed very well preserved. Some of them have been dated. The oldest one was made 1902, but most of them are from 1920-30. (There may also very well be older ones yet not found).
The pines growing on the peat does have an unusual annual ring pattern, which makes it difficult to date them towards the standard Pine chronologies of the area, for instance swed305. Therefore it was necessary to build up a special PISY collection, Petmyra (PISY-ref), for this work.