Gader Valley is a long valley in the Greater Fatra Range in Central Slovakia. It is accessible from the village of Blatnica. The valley is the gateway to the peaks of Tlstá and Ostrá. Its upper part, from the merger with the Selenec Valley, is named Dedošová. In Gader Valley, there are almost all of the protected species of animals and plants that occur throughout the Great Fatra: 3,000 species of invertebrates, 110 species of birds, and 60 mammalian species. The Tlstej complex was declared a National Nature Reserve in 1972.