Seventeen brown bear dens were studied in the Kronotsky Nature Reserve (Russian Far East). The majority of dens were excavated in the ground. The dens were located mainly in the upper part of slopes with southwest aspects in birch forests, dwarf Siberian pine and alder patches. The structure of the dens was typical for brown bear ground dens. There are places in the basin of Shumnaya River in Kamchatka where brown bears prefer to set up their dens.