Here we present a case study from Kilpisjärvi Sub-arctic Biological Station, Finland. Kilpisjärvi Sub-arctic Biological Station (69°03′ N 20°48′ E) is located in northwest Finnish Lapland. Kilpisjärvi research station as well as other Finnish research stations have many ecological long-term monitoring datasets from several decades. The gathering of these datasets has started in almost all cases from a single research question and belonged to one person. For different reasons, the stations has continued the monitoring, but the data itself has remained unused. Not using the data has led to several problems, where one is the reusability of it. The main issues with data is the lack of proper description of the data and the method, meaning that the metadata is missing. Also quite often, there is no proper folder structure for different datasets. Data itself is stored in several excel files and one excel file contains several sheets. Files are also different for different years. In our case study, we want to explain how we worked our way towards FAIR and reusable data using a long-term bilberry monitoring dataset as an example. This dataset consists of bilberry yield and flowering data. The data gathering started in 1973 and is one of the ongoing monitoring schemas at the Kilpisjärvi station.