The Canalway Trail System offers hundreds of miles of scenic trails and numerous parks for walking, cross-country skiing, and other recreation along the New York State Canal System, whose four historic waterways are the Erie, Champlain, Oswego, and Cayuga-Seneca canals. Spanning 524 miles across New York State, the canal system links the Hudson River with Lake Champlain, Lake Ontario, the Finger Lakes, the Niagara River, and Lake Erie, and cooperative efforts by the New York State Canal Corporation, volunteers, local governments, and federal and state agencies created this trail network for public use. At Fort Plain, the locks show how canal operations changed over time: the first Erie Canal locks were stone structures 15 feet wide and 90 feet long, while the concrete lock built during modernization in the early 20th century is nearly 45 feet wide and 300 feet long, with electric motors opening metal gates weighing more than 20 tons. The area around the locks also changed as homes of locktenders and their families, sheds, barns, and canal stores gave way to power houses, lock operator control stands, and electric cabinets. During construction of the Erie Barge Canal in the early 20th century, engineers designed moveable dams to control river flow for navigation, holding back water in large ponds when the canal is open and allowing the river to resume its natural course in winter when the dam panels are lifted out. After 1908, modernization shifted the canal into the Mohawk River, and although much of the old canal route at Fort Plain was abandoned and filled in, some nearby portions remain visible. In the 19th century, the Erie Canal also crossed rivers, creeks, and ravines by aqueducts, including one at Fort Plain, stone structures so striking that Thomas Cole called them the "castles of the United States," destined to tell of the enterprise and industry of the present generation.