The lake's east side has pristine boreal forests and rivers that were in 2018 inscribed as Pimachiowin Aki, a UNESCO World Heritage Site.

The lake is 416 km (258 mi) from north to south, with remote sandy beaches, large limestone cliffs, and many bat caves in some areas.

[6] Lake Winnipeg drains northward into the Nelson River at an average annual rate of 2,066 cubic metres per second (72,960 cu ft/s) and forms part of the Hudson Bay watershed, which is one of the largest drainage basins in the world.

[9] Families represented include lampreys (Petromyzontidae), sturgeon (Acipenseridae), mooneyes (Hiodontidae), minnows (Cyprinidae), suckers (Catostomidae), catfish (Ictaluridae), pike (Esocidae), trout and whitefish (Salmonidae), troutperch (Percopsidae), codfish (Gadidae), sticklebacks (Gasterosteidae), sculpins (Cottidae), sunfish (Centrarchidae), perch (Percidae), and drum (Sciaenidae).

[15] Lake Winnipeg provides feeding and nesting sites for a wide variety of birds associated with water during the summer months.

Large populations of waterfowl and shorebirds use the sand bars east of Riverton as a staging area for fall migration.

[20] The Netley-Libau Marsh, where the Red River enters Lake Winnipeg, is used by geese, ducks and swallows to gather for the southward migration.

The Gull Bay Spits, south of the town of Grand Rapids, are considered nationally significant nesting sites for this species.

[citation needed] Lake Winnipeg lies along one of the oldest trading routes in North America to have flown the British flag.

With the establishment of the Second British Empire after Britain's loss of the Thirteen Colonies, a significant increase in trade occurred over Lake Winnipeg between Rupert's Land and the United States.

A number of pleasure beaches are found on the southern end of the lake, which are popular in the summer, attracting many visitors from Winnipeg, approximately 80 km south.

Lake Winnipeg is widely recognized as a premier angling destination, attracting anglers from around the globe[30] "targeting it's abundant walleye, sauger and channel catfish populations"[31] along with northern pike, yellow perch, gold eye, mooneye.

[33] and as of 2018 that had grown to nearly 100,000 adult anglers fishing Lake Winnipeg and its southern tributaries, adding $102,000,000 to the provincial GDP supporting some 1,500 jobs.

[35] Recent introduction of new angling regulations aim to ensure the sustainability of the fishery, with an extended season closure during the spring walleye spawn, reduced possession limits, and an end to the retention of trophy sized fish.