Linked from
The 5 pages that link to Hudson Bay drainage basin, each with the reason it gives.
Hudson BayBroader topic: Its immense freshwater input affects the bay’s salinity and circulation.
Lake WinnipegNarrower topic: Lake Winnipeg forms part of this continental drainage system.
Hudson StraitRelated: Freshwater from this basin reaches the Atlantic through Hudson Strait.
Saskatchewan RiverNarrower topic: The Saskatchewan belongs to this continental-scale watershed.