Marion Lake 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.

Loading depth chart…

Recent catches at Marion Lake

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 Marion Lake on the board.

Fishing Marion Lake: what the data says

68-acre lake in Flathead County, Montana. The lake tops out around 150 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. The season-by-season read for each species follows, from the map's own numbers.

The outline encloses 68 acres, worked by 1.5 miles of shoreline. A shoreline index of 1.3 says round and simple: fish relate to depth changes here, not shoreline features. The shallow band under 15 ft claims about 7% of the surface — that's where the groceries are. The basin spans about 0.7 mi end to end and 0.2 mi across at its widest. It sits in Flathead County. Dickey Lake (Flathead) sits 2 mi northwest — the closest neighbouring chart.

Cutthroat Trout fishing at Marion Lake

Spring puts cutthroat trout in skinny water — 3 to 15 ft is the zone. Warm water sends them out to 10 to 35 ft; cold water stacks them in 10 to 40 ft. Break off the point is the standout, a drop-off at roughly 139 ft, rated good for summer cutthroat trout. Plan around early morning and the evening in the warm months. A trolled spoon (small) or an inline spinner covers the summer program.

Season	Depth	Best window	Start at	Go-to baits
Spring	3 to 15 ft	dawn & dusk	open water	Inline spinner (silver/gold), Small spoon
Summer	10 to 35 ft	dawn & dusk	Break off the point (139 ft)	Trolled spoon (small), Inline spinner
Fall	5 to 25 ft	dawn & dusk	Main-lake point (56 ft)	Casting spoon, Inline spinner
Winter	10 to 40 ft	dawn	Break off the point (139 ft)	Small jigging spoon, Marabou jig

Rainbow Trout fishing at Marion Lake

Early season rainbow trout use the shallows, holding in 5 to 20 ft. Expect a summer slide to 8 to 30 ft, then a winter hold in 8 to 40 ft. Put Shallow bay flat first on the milk run — a feeding flat near 12 ft that grades good for spring. In summer the feeding windows fall in early morning and the evening. Tie on a dodger + spoon (deep troll) or a flutter spoon and you're in the game.

Season	Depth	Best window	Start at	Go-to baits
Spring	5 to 20 ft	dawn & dusk	Shallow bay flat (12 ft)	Inline spinner (silver), Small spoon
Summer	8 to 30 ft	dawn & dusk	Shallow bay flat (12 ft)	Dodger + spoon (deep troll), Flutter spoon
Fall	10 to 35 ft	dawn & dusk	open water	Casting spoon, Jerkbait over shoals
Winter	8 to 40 ft	dawn	Break off the point (139 ft)	Jigging spoon, Tube jig (white)

Notable structure

Structure-wise the chart holds 5 features, led in depth by Deep basin at roughly 140 ft.

Deep basin: deep basin, around 140 ft
Break off the point: drop-off, around 139 ft
Main-lake point: point, around 56 ft
Shallow bay flat: feeding flat, around 12 ft
Back-bay flat: feeding flat, around 9 ft

Marion Lake 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 Marion Lake specifically, so confirm the current rules before you fish.

Check the official Montana fishing regulations →

Common questions

How deep is Marion Lake?

Marion Lake is about 150 ft (46 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 Marion Lake?

Anglers target cutthroat trout, rainbow trout on Marion Lake.

Where is the best fishing spot on Marion Lake?

Shallow bay flat is the top-rated area: a feeding flat in about 12 ft of water that rates good for rainbow trout in spring. The interactive chart above rates every spot for each species and season.

When is the best time to fish Marion Lake?

For cutthroat trout, the summer bite is best in early morning and the evening. 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 Marion Lake?

Fishing on Marion Lake 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

Dickey Lake (Flathead) 2 mi · Hungry Horse Reservoir 8 mi · West Tranquil Basin Lake 8 mi · East Tranquil Basin Lake 9 mi · Handkerchief Lake 11 mi · Cliff Lake (Flathead) 12 mi · Skiumah Lake 13 mi · Black Lake 13 mi · Wildcat Lake 14 mi · Margaret Lake (Flathead) 14 mi · Pilgrim Lake 14 mi · Birch Lake 14 mi

See how Marion Lake stacks up: best rainbow trout lakes in Montana · best cutthroat trout lakes in Montana

More water nearby: Flathead County fishing maps (55 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.