Its drainage basin is 108,500 square kilometres (41,900 sq mi) and it has a mean discharge rate of 1,370 cubic metres (48,000 cu ft).

Moosonee, on the north bank of the river, is the northern terminus of the Polar Bear Express railway route which begins at Cochrane, Ontario.

The funnel-shaped outline of Hudson and James bays causes birds migrating from the Arctic to concentrate at the southern end of James Bay each autumn, particularly in the late autumn, where the extensive coastal wetlands provide critical staging and moulting areas for migrating lesser snow geese, dabbling ducks and shorebirds such as red knot, short-billed dowitcher, dunlin, greater yellowlegs, lesser yellowlegs, ruddy turnstone, and American golden plover.

[2] At mile 142 of the Polar Bear Express railway route there is a small settlement called Moose River.

This settlement is just before a large railway bridge that crosses Moose River and is a flag stop on the Polar Bear Express rail route.