The Columbia River is an important transportation route in the Pacific Northwest of the United States, and barges are one of the primary modes of transportation on the river. Barges on the Columbia River carry a variety of goods, including agricultural products, timber, petroleum, and other bulk commodities. The Columbia River barge system is part of the larger inland waterways transportation system of the United States, which includes more than 25,000 miles of navigable waterways and over 240 locks and dams. The barges used on the Columbia River are typically flat-bottomed and can be up to 300 feet long and 54 feet wide. The Columbia-Snake River System, which includes the Columbia River and its major tributary, the Snake River, has four main lock and dam structures that help to maintain navigability for barges and other vessels. These locks allow barges to move up and down the river, as well as through the various reservoirs created by the dams.