To study the peculiarities of a local beaver population abundance and dynamics of beaver site use in a hilly landscape, there were beaver sites registered yearly, with their use, habitat and type of the main shelter established on the territory (Eastern Lithuania) covering an area of 2.4 thousand ha during the period of 1983–1994 and the year 2001. The population density having increased, abandoned beaver sites made up 44–58% of their total number. The number of active beaver sites in swamps, small and shallow rivulets and ditches, with a lodge being the main type of the main shelter, increased respectively (up to 74%). The use of beaver sites proved to be very dynamic, the mean duration of their continuous use amounting to 2.61 ± 0.23 (±SE) years. A great part (≥43%) of abandoned beaver sites were after a short period of time (2.72 ± 0.29 years on the average) recolonized by beavers again.