Ohio's hydrology is influenced by its location in the midwestern United States, experiencing a humid continental climate. Major surface waters include Lake Erie and the Ohio River, which flows through the state and serves as a border with neighboring Kentucky and West Virginia. Other major rivers and tributaries include the Muskingum River, the Cuyahoga River, and the Maumee River. The state's hydrology is impacted by numerous reservoirs and dams, including the Hoover Reservoir and the Grand Lake St. Marys. Snowpack and watershed data are also relevant in Ohio's hydrology, with the state experiencing frequent snowfall in the winter months and a variety of watersheds throughout the state.