Heart Lake (Lewis and Clark) Depth Map & Fishing Spots (MT)

Hatch outlook

Grasshoppers (east-side summer)Active window

Typical here: Jul 1 – Oct 15 · until the hard frosts of mid-October; on the Missouri, August hoppers fish mid-river, not the banks

adultall day in high summer, best when afternoon wind knocks bugs onto the water

Pulls fish to the windward grassy banks and edges for months — fish the bank the wind blows ONTO.

The friendliest crossover of the summer: on lakes, drift the windward bank with a bubble-and-foam-hopper — the bubble's splash doesn't hurt a hopper presentation. On rivers, the same rig dead-drifted along the undercut grass banks, or small gold spinners under the banks between rises.

The event happens over grassy banks, undercut edges and windward shorelines

Spruce MothActive window

Typical here: Jul 20 – Aug 31 · a conifer-forest event — it needs fir and lodgepole on the banks, so it's a Rock Creek / Blackfoot / upper Bitterroot specialty

adultmorning through midday — moths don't enter the water willingly — landings are sporadic and near the conifer banks; fish the imitation LOW in the film with minimal floatant, even fully drowned, with a little movement

When the moths show, just about every run produces — large trout key on them so hard that one pattern carries the whole box for two weeks.

Honest limit: a small drowned-surface moth has no lure analog. The workable rig is a casting bubble with a drowned moth pattern along the timbered banks in the morning; otherwise fish spinners early and late and leave the moth window to the film.

2–3 weeks at best, and day-to-day — fish key on the moths when they show and vanish with them

The event happens over banks under conifers — the moths rarely reach mid-river

Recommendations come from depth structure and seasonal species behavior. Treat them as a starting point, not a guarantee. Contours here are interpolated from real agency depth surveys (state DNR / USACE). Never use for navigation. Always check local regulations.

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Recent catches at Heart Lake (Lewis and Clark)

Shared by DepthScout anglers. Exact spots stay private, always.

No shared catches here yet — be the first.Log a catch from the map above and share it to put Heart Lake (Lewis and Clark) on the board.

Fishing Heart Lake (Lewis and Clark): what the data says

31-acre lake in Lewis and Clark County, Montana. The lake tops out around 50 ft. The depth chart is built from real state fisheries GPS surveys, so the humps, channels and drop-offs you see are measured, not guessed. Species by species, here's what the data says the year looks like.

On the chart, Heart Lake (Lewis and Clark) draws 32 acres inside 1.5 miles of shoreline. The shoreline is moderately structured (index 1.9) — enough points and pockets to pattern. Roughly 21% of the water is 15 ft or less, the band where the food chain lives. Tip to tip the water measures near 0.4 mi with a 0.2-mi widest point. You'll find it in Lewis and Clark County. For a second option, Parker Lake lies 4 mi west.

Arctic Grayling fishing at Heart Lake (Lewis and Clark)

In spring, arctic grayling run shallow here, mostly 2 to 10 ft. Summer pushes them deeper, 3 to 15 ft, and winter fish settle into 8 to 25 ft. Break off the point is the standout, a drop-off at roughly 20 ft, rated prime for fall arctic grayling. Time it for the evening and early morning. You won't need more than a dry fly (parachute adams, elk hair caddis) or a small inline spinner most summer days.

Season	Depth	Best window	Start at	Go-to baits
Spring	2 to 10 ft	midday & dusk	Shallow bay flat (10 ft)	1/16 oz spinner (silver), Small dry fly (Adams, Griffith's)
Summer	3 to 15 ft	dusk & dawn	Shallow bay flat (10 ft)	Dry fly (parachute Adams, elk hair caddis), Small inline spinner
Fall	6 to 20 ft	midday	Break off the point (20 ft)	Small spoon, Beadhead nymph under indicator
Winter	8 to 25 ft	midday & dawn	Break off the point (20 ft)	Tungsten jig + waxworm, Small jigging spoon (gold)

Cutthroat Trout fishing at Heart Lake (Lewis and Clark)

Come spring, look for cutthroat trout tight to the bank in 3 to 15 ft. Expect a summer slide to 10 to 35 ft, then a winter hold in 10 to 40 ft. Start at Break off the point. It's a drop-off holding about 20 ft of water and rates prime come summer. Prime time lands in early morning and the evening. A trolled spoon (small) or an inline spinner is the honest summer answer here.

Season	Depth	Best window	Start at	Go-to baits
Spring	3 to 15 ft	dawn & dusk	Main-lake point (19 ft)	Inline spinner (silver/gold), Small spoon
Summer	10 to 35 ft	dawn & dusk	Break off the point (20 ft)	Trolled spoon (small), Inline spinner
Fall	5 to 25 ft	dawn & dusk	Main-lake point (19 ft)	Casting spoon, Inline spinner
Winter	10 to 40 ft	dawn	Break off the point (20 ft)	Small jigging spoon, Marabou jig

Notable structure

The chart marks 4 structure features on Heart Lake (Lewis and Clark); the deepest is Deep basin at about 49 ft.

Deep basin: deep basin, around 49 ft
Break off the point: drop-off, around 20 ft
Main-lake point: point, around 19 ft
Shallow bay flat: weed flat, around 10 ft

Heart Lake (Lewis and Clark) fishing regulations

Season dates, license requirements, and size and bag limits for Montana waters are set by the Montana Fish, Wildlife & Parks — and special regulations can apply to Heart Lake (Lewis and Clark) specifically, so confirm the current rules before you fish.

Check the official Montana fishing regulations →

Common questions

How deep is Heart Lake (Lewis and Clark)?

Heart Lake (Lewis and Clark) is about 50 ft (15 m) deep at its deepest point. The depth chart here comes from real state fisheries GPS surveys, so the contours reflect measured depths.

What fish are in Heart Lake (Lewis and Clark)?

Anglers target arctic grayling, cutthroat trout on Heart Lake (Lewis and Clark).

Where is the best fishing spot on Heart Lake (Lewis and Clark)?

Break off the point is the top-rated area: a drop-off in about 20 ft of water that rates prime for cutthroat trout in summer. The map above holds the full rated-spot list for every species and season.

When is the best time to fish Heart Lake (Lewis and Clark)?

For arctic grayling, the summer bite is best in the evening and early morning. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.

What are the fishing regulations for Heart Lake (Lewis and Clark)?

Fishing on Heart Lake (Lewis and Clark) is regulated by the Montana Fish, Wildlife & Parks. Check the official Montana regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.

Nearby waters

Parker Lake 4 mi · Coopers Lake 13 mi · Bean Lake 16 mi · Canyon Lake (Lewis and Clark) 17 mi · Lake Otatsy 18 mi · Camp Lake (Lewis and Clark) 18 mi · Browns Lake 21 mi · Nevada Reservoir 25 mi · Blackfoot River 26 mi · Upsata Lake 27 mi · Willow Creek Reservoir 31 mi · Cottonwood Lake, Middle 33 mi

See how Heart Lake (Lewis and Clark) stacks up: best arctic grayling lakes in Montana · best cutthroat trout lakes in Montana

More water nearby: Lewis and Clark County fishing maps (9 charts). Browse all Montana fishing maps or see every water on DepthScout. Bathymetry credit: state fisheries survey programs. How we build these maps. Fish here with a sonar unit that logs? Send us your depth data and we'll improve this chart, credited to you. For fishing guidance only, never navigation.