 The third subdivision includes the Oswego River and its tributaries, and the small streams flowing into Lake Ontario between the Genesee and Oswego rivers.The basin of the Oswego includes most of the inland lakes, which form a peculiar feature of the landscape in the interior of the state.The principal of these lakes are Cayuga, Seneca, Canandaigua, Skaneateles, Crooked, and Owasco lakes, all occupying long, narrow valleys, and extending from the level land in the center far into the highland region of the south (many of those lakes just mentioned are also part of the Finger Lakes).