The park became a dark-sky preserve in 2009. This was during the International Year of Astronomy. The park was chosen by the Royal Astronomical Society of Canada. It became Saskatchewan's second dark-sky preserve. In 2009, Parks Canada also added black-footed ferrets back to the park. They added 34 ferrets. People thought that the black-footed ferret was extinct. This is because the last time they were seen was in 1937 in Saskatchewan. Scientists from the United States began working on bringing them back to the wild. When Parks Canada added black-footed ferrets back to Grasslands National Park, there were already ferrets that were being added to places in the United States and Mexico. The scientists were working to bring back the black-footed ferret for many years. The people working at Parks Canada were working on bringing them back for many years.