Some waters you fish for numbers; Kootenay Lake you fish for one fish of a lifetime. This is the big trophy water of the Kootenays — a fjord-deep lake a hundred kilometres long, walled by the Selkirks on one side and the Purcells on the other, holding the largest strain of rainbow trout that has ever swum. It is not a place you learn in an afternoon, and it does not give its best fish easily. That is exactly the point.
A lake the size of a fjord
At roughly 104 kilometres end to end, Kootenay Lake is among the largest lakes in British Columbia — a long, cold, glacially-carved trench between two of the province's great mountain ranges. The Ktunaxa fished it long before it had its English name, taking sturgeon and kokanee from water that has always been generous to those who understood it. Today it remains, first and foremost, a boat fishery: the shorelines drop away fast, the fish range the open water column, and the classic approach is to troll, often from a guided charter, rather than to wade and cast.
The headline fish
Kootenay Lake's reputation rests on the Gerrard rainbow — a wild, piscivorous strain that grows to around 35 pounds, the largest rainbow trout anywhere on earth. They share the lake with big bull trout and with the kokanee that feed them both. The whole food web pivots on that little land-locked sockeye: when the kokanee are strong, the lake grows giants; when they falter, everything above them thins.
A fishery rebuilt by hand
The lake you fish today is, in part, an engineered recovery. Through the mid-twentieth century the system was knocked off balance: the invasive shrimp Mysis arrived in 1949, and the Duncan (1967) and Libby (1973) dams stripped nutrients from the inflows, starving the plankton at the base of the food web. The kokanee crashed, and the trophy fishery with them.
The response was unusually direct. Since 1992 on the North Arm and 2004 on the South, the province has run a Nutrient Restoration Program, adding measured nitrogen and phosphorus to rebuild the Daphnia-to-kokanee food chain by hand. It has worked, slowly: by 2019 the spawner count had climbed to around 63,300 fish between Meadow Creek and the Lardeau — the best since 2015, though still short of historic highs — with bull trout laying 423 redds across eight tributaries. Recovery, not restoration to what once was, is the honest word.
When the kokanee are strong, the lake grows giants.
That is why anglers are asked to be part of the machinery. Through the Angler Incentive Program, the province and its partners reward the harvest of rainbow and bull trout — turn in the heads and you're entered in a prize draw — to ease predation while the kokanee climb back. On most trophy water you release the big fish; here, taking a rainbow can be the conservation-minded choice. Read the current rules before you decide.
How it's fished
This is a downrigger lake. The productive game is to troll the cold water column with a sounder, running spoons, plugs and bucktails at the depth where the kokanee schools hold and the big rainbows and bull trout shadow them. Structure, drop-offs and bait balls are the map. Fly anglers are not shut out entirely — creek mouths and estuary flats in the cooler shoulder seasons can bring fish within reach of a cast — but for the marquee Gerrards, the boat and the rigger are the tools.
Fish the recovery
Getting on the water
From the Creston end, Kuskanook Harbour is the closest ramp, with Boswell another option down the east shore. Further north the launches multiply — Sunshine Bay, Balfour, Queens Bay, Kootenay Bay, Kaslo, Lardeau — and the free Kootenay Bay–Balfour ferry, the longest inland ferry ride in North America, doubles as a way to read the water. Bank anglers can find fish at the creek mouths — Lockhart, Sanca, Coffee, Kaslo — where cold tributaries meet the lake.
Sources & further reading: Explore Creston Valley; BC government fisheries and nutrient-restoration data; Go Fish BC; guide/operator source checks; and the BC Freshwater Fishing Regulations, Region 4 (2025–2027). Recovery figures reflect 2019–2020 reporting — limits and closures change, so always check the current synopsis.
