The Nelson estuary is broad and shallow, so port facilities would have to be constructed on artificial islands created in the middle of the river, that would require a causeway approximately a kilometre long to reach.

The river was named by Sir Thomas Button, a Welsh explorer from St. Lythans, Glamorganshire, who wintered at its mouth in 1612, after Robert Nelson, a ship's master who died there.

At that time, the Cree people who lived along its banks called it Powinigow or Powinini-gow, which may have meant "the Rapid Strangers' river".

One 1670 expedition organized by the newly-chartered Hudson's Bay Company and guided by the French fur trader and adventurer Pierre-Esprit Radisson successfully reached the Nelson estuary.

Landing in September, the first overseas governor of the Hudson's Bay Company, Charles Bayly, nailed a brass plate of the English royal arms to a tree, formally claiming the territory for England.

After his pivotal role in establishing the Hudson's Bay Company, Pierre Esprit Radisson, noted French explorer, was chief director of trade at Fort Nelson during one of his sustained periods of service to England.

What was once a highway for hunters is now dangerous to travel in winter, as the location of ice pockets created by flooding and retreating water cannot be predicted.