The mouth of the Kegaska River is located six and a half kilometers from the village of the same name, some 30 kilometers east of Natashquan. The river flows for some 80 kilometers through the hills, then meanders through marshy lowlands before emptying into the Gulf of St-Laurent.
The name "kegaska" comes from the Innu word "quegasca", meaning "a shortcut or easy passage at high tide between the mainland and the islands". At the river's mouth, numerous coves and bays, such as Kegaska Harbour, Baie et Anse aux Huîtres and Baie et Anse de Kegaska, are home to seagrass beds and salt marshes that are home to a rich diversity of wildlife. The site's sandy beaches are also renowned for birdwatching, marine mammal watching and soft-shell clam harvesting.
The Kegaska River is a prime habitat for salmon, which have a run of around 100 km, including tributaries. Sport fishing is practiced along the first 13 kilometers, by boat or wading, in four tide-influenced pools. The average weight of salmon caught varies from 2.5 to 4 kilograms. The Leslie Foreman Fishing Club, named after a Nova Scotia family who settled here in 1855, holds exclusive fishing rights on the portion of the river up to Kegaska Lake, some 30 kilometers from the estuary.