Hudson Bay, a gulf, or rather inland sea, in the north-east of North America, is completely landlocked except on the north, where Southampton Island and Fox Channel lie between it and the Arctic Ocean, and where Hudson Strait, running 500 miles south-east, connects it with the Atlantic. Including its south-eastern extension, James's Bay (q.v.), it measures about 1000 miles in length and 600 in average width, and has an area of some 500,000 sq. m. The eastern shore, called the East Main, is for the most part rocky, and is fenced with several small islands; the western shore, the West Main, is flat. This sea is the great drainage reservoir of the Canadian North-west Territories, its chief feeders being the Churchill, whose deep and narrow mouth forms the best harbour on the shores of Hudson Bay, and the Nelson, of whose total course of 400 miles only 70 or 80 are navigable. The fur trade began with the Hudson Bay Company (founded 1670); fish-oil has also been exported. It has been proposed to open up direct communication from England with Manitoba and the North-west of Canada by way of Hudson Bay and Strait (navigable only about three months annually, by reason of the ice); the scheme providing for a railway from Winnipeg to Fort Nelson on the bay, a distance of 650 miles.