The field of study of this project is the municipal management of the nature that is protected by the Law on Nature Protection. It is examined which methods and arguments the municipalities are using when deregistration of the § 3 areas. The underlying basis of the projects analysis is data from Danmarks Arealinformation, the practice of deregistration in six of the municipalities from Northern Jutland and interviews with key persons. The analysis results show that the municipalities use different methods when updating changes to Danmarks Arealinformation. Additionally it is estab-lished that deregistration of § 3 protected areas has multiple causes. Particularly, that the § 3 protection is wrongly recorded in areas that is not originally considered to be covered by the § 3 protection. Furthermore, it has been established that the mu-nicipalities to a great extent use series of aerial photographs to evaluate whether the § 3 protec-tion can be sustained or not. This basis for decision has proved to be inadequate, because it can be dif-ficult to determine the status of the areas at the time of appointment in 1992. For that reason the municipalities have difficulties satisfying the burden of proof, and in consequence, to sustain the § 3 protection.