Norwegian production of sheep, and to some extent also cattle and goat, is based on grazing on extensive pastures in mountain and forest areas during summertime. In order to reduce loss of animals and reduce herding costs, farmers receive state support for organizing themselves in grazing entities.

Each grazing entity is mapped as a polygon feature with attributes reflecting the total number of types of animals released for grazing and the total number and percentage of animals lost. Reasons for losses are not classified, but are mainly due to sickness, accidents and predators.

Currently there are roughly 800 grazing units around Norway. Together they entail roughly 75% of all sheep, 30% of all cattle and goats sent on extensive pastures during summer time.

Each grazing entity provides boundaries of their grazing area on national topographic maps at scale 1:50.000. The map is updated each year. The boundaries are digitized and coupled to statistics on animals kept and lost in national registries by agencies under the Directorate of Agriculture. Data is stored and disseminated by NIBIO. The grazing area is not equivalent to farm property areas.