Hudson River Estuarine Research Reserve System as the Hudson River National Estuarine Research Reserve. The Hudson River is navigable by large steamers up to Troy, and by ocean-faring vessels to the Port of Albany. The original Erie Canal, opened in 1825 to connect the Hudson with Lake Erie, emptied into the Hudson at the Albany Basin, just south of the Federal Dam in Troy (at mile 134). The canal enabled shipping between cities on the Great Lakes and Europe via the Atlantic Ocean. The New York State Canal System, the successor to the Erie Canal, runs into the Hudson River north of
Great Lakes shipping from January to March. Some icebreakers ply the lakes, keeping the shipping lanes open through other periods of ice on the lakes. The Great Lakes are also connected by the Chicago Sanitary and Ship Canal to the Gulf of Mexico by way of the Illinois River (from the Chicago River) and the Mississippi River. An alternate track is via the Illinois River (from Chicago), to the Mississippi, up the Ohio, and then through the Tennessee–Tombigbee Waterway (a combination of a series of rivers and lakes and canals), to Mobile Bay and the Gulf of Mexico. Commercial tug-and-barge traffic on