Lake trout are char, Salvelinus namaycush, and they are built for a life that no other fish on this site leads: decades long, in water colder than fifty degrees, often a hundred feet or more down, eating other fish. They grow slowly, mature late, and reach sizes no stream trout approaches. They are also, for most of the year, out of reach of anything but a boat with a fish finder and a heavy jig or a downrigger. Two short windows change that, one after ice-out and one before the fall spawn, and those windows are what the fly angler and the shore angler plan around.
A char from the North, introduced across the West
Lake trout are native to the glaciated lakes of Canada, Alaska, the Great Lakes and the Northeast. Nothing about them is native to the Rocky Mountain West; every population here was introduced, some deliberately as a trophy fishery and one, in Yellowstone Lake, illegally and with disastrous effect on the native cutthroat. GBIF records place the species in Wyoming, Colorado, Montana, California, New Mexico, Idaho, Utah, Nevada, Oregon, Washington and Arizona among Western states, most of those from a handful of big, deep, cold lakes. Mackinaw is the older Western name and you will still hear it in Washington and Oregon.
Their biology sets the rules. Lake trout are a fall spawner, broadcasting eggs over rocky shoals and rubble at night rather than digging a redd, which is why they can spawn in deep water where nets cannot reach them. They hold in the coldest oxygenated layer of a lake, which in summer is below the thermocline. They eat whatever fish is abundant: kokanee, cisco, whitefish, juvenile trout, and, in Yellowstone Lake, young cutthroat.
The lakes on this site that list lake trout
- Flaming Gorge Reservoir, Utah and Wyoming: the best-known lake trout water on the site, a deep canyon reservoir on the Green River with a reputation for very large fish, mostly taken by deep trolling and jigging in the canyon sections.
- Fremont Lake, Wyoming: a glacial lake below the Wind River Range, hundreds of feet deep, where mackinaw move shallow in September and October.
- Flathead Lake, Montana: the largest natural lake in the West, with lake trout in the transition zones between the deep basin and the shelves, and a native westslope cutthroat and bull trout population the lake trout compete with.
- Jackson Lake, Wyoming: Grand Teton's big lake, where lake trout are the dominant large fish and come within reach of a sinking line in spring and fall.
- Lake Chelan, Washington: the deepest lake in the state, with mackinaw and kokanee in the cold lower basin.
- Odell Lake, Oregon: a Cascade summit lake at Willamette Pass that the page calls Oregon's finest mackinaw water, with a fall fly-rod window.
- Yellowstone Lake, Wyoming: the exception. Lake trout here are an invasive that collapsed the native Yellowstone cutthroat, and the park runs a large netting program against them. The page asks anglers to kill every lake trout caught; confirm the current rule with the park before you go.
Fish Lake in Utah holds splake, the lake trout and brook trout hybrid, which behaves more like a brookie and comes to a stripped Woolly Bugger along the weed edges. The Wyoming and Montana hubs list every recorded water in those states.
Jigging: the most effective method most of the year
From late spring through summer, lake trout are deep and the fastest way to fish for them is vertically. Find them first: a fish finder marking fish or bait near the bottom in sixty to a hundred and fifty feet, along a drop-off, a submerged point or the edge of a channel. Then drop a heavy jig straight down and work it within a few feet of the bottom. Tube jigs in white or glow, heavy jigging spoons, and large soft plastics on jig heads of one to three ounces are the standard tools. Lift, let it fall on a semi-slack line, and watch the line, since most takes come on the drop. A medium-heavy spinning or casting rod with braided line and a fluorocarbon leader gives the sensitivity to feel a fish mouth the jig a hundred feet down.
Trolling: covering water on the big reservoirs
On Flaming Gorge, Chelan and Flathead, trolling covers the most water. Downriggers put a large spoon, plug or flasher-and-fly combination at the depth the fish finder shows, usually near the thermocline in summer and deeper as the season warms. Speeds are slow, well under two miles an hour, because lake trout will not chase. Trolling is also the way to find concentrations before switching to the jig.
The spring and fall shallow windows
For a few weeks after ice-out, and again in September and October as the water cools toward spawning temperature, lake trout come into water shallow enough to reach from shore, a float tube or a small boat with a sinking line. This is the fly angler's season, and every lake page above names it. Fremont, Odell and Flaming Gorge all point to September and October; Jackson Lake to spring and fall both. The tactic is simple. A full-sinking or heavy sink-tip line, a short leader of 0x or heavier, and a large baitfish streamer: tube flies, articulated leeches, Clouser Minnows and marabou streamers in sizes 2 through 2/0, in white, chartreuse or olive over white. Cast toward rocky points, shoals and inlet drop-offs, count the fly down, and strip slowly with long pauses. The takes are heavy rather than sharp. A 7- or 8-weight handles the line and the fish.
The same window applies to conventional gear. Casting large spoons and swimbaits from rocky shorelines at dawn in the fall is how a lot of shore anglers meet their first big lake trout.
Handling and the rules that vary
A lake trout brought up from deep water has expanded its swim bladder and may not survive release. If you intend to release fish, fish the shallow windows or shallower structure; if you are jigging deep, plan to keep what the rules allow. Those rules are the most variable on this site: Yellowstone Lake asks you to kill every one, Flaming Gorge has used size-based limits in the past to thin small fish while protecting big ones, and other lakes fall in between. Check the state agency or the park for the specific lake before the trip, and check again the following year, because lake trout management changes as the fisheries do.