Williston Lake is the largest lake in British Columbia and one of the largest man-made lakes in the world. Created in 1968 when the W.A.C. Bennett Dam was built, the reservoir spans approximately 300 kilometres in length and covers an area of 1,773 square kilometres. It occupies the Rocky Mountain Trench and is formed by the flooding of three river valleys — the Peace, Parsnip, and Finlay — giving it a distinctive multi-armed shape with three major reaches.

Several boat launches provide access for paddlers. Alexander Mackenzie's Landing, accessible both by road and water, offers a boat launch, campground, picnic area, and sandy beach, and is open from May 15 to October 15. The Dunlevy Inlet boat launch on the north shore of the Peace Reach is accessible via Twelve Mile Road through Butler Ridge Provincial Park. The Elizabeth Creek boat launch is located just across the W.A.C. Bennett Dam. Both the Elizabeth Creek and Dunlevy launches are only usable at high reservoir levels. The Kwadacha boat launch at the Finlay River near Fort Ware provides access to the northern reaches. Additional paddling access points include Cut Thumb Bay, Finlay Forks, and Six Mile Bay.

Safety is a significant concern on Williston Lake. Sudden strong winds can generate high waves, and the lake contains substantial floating debris and deadheads — a direct consequence of the river banks not being logged before the reservoir was flooded. This debris hazard remains ongoing. Rising and falling water levels have created severely eroded shorelines, and sandstorms are common on windy days. Paddlers should exercise extreme caution throughout the lake.

The aesthetic character of the lake reflects its artificial origins: the shorelines are unnatural in appearance, prone to erosion, and the fluctuating water levels leave exposed, unstable banks. Wildlife including deer and Stone's Sheep are seen in the surrounding region. The W.A.C. Bennett Dam visitor centre offers free scheduled underground tours, and the Hudson's Hope Museum features a fossil collection. Dunlevy Provincial Park at the east end of the lake provides a picnic and day-use area with a boat ramp. Two lodges on the lake — Torwood Lodge and Williston Lake Resort — offer accommodation options for multi-day trips.