Fatty 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.

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Recent catches at Fatty 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 Fatty Lake on the board.

Fishing Fatty Lake: what the data says

22-acre lake in Lake County, Montana. The lake tops out around 60 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 22 acres, worked by 0.7 miles of shoreline. At index 1.1 the outline is almost a bowl — read the depth changes, not the shoreline. The shallow band under 15 ft claims about 23% of the surface — that's where the groceries are. Call it 0.3 mi long by 0.2 mi wide at the broadest reach. It sits in Lake County. Shay Lake sits 5 mi east — the closest neighbouring chart.

Walleye fishing at Fatty Lake

Start shallow in spring: walleye sit in 4 to 15 ft that time of year. Warm water sends them out to 15 to 35 ft; cold water stacks them in 20 to 40 ft. Top water on the chart: Break off the point, a drop-off in the 41 ft range, prime in fall. Fish it in the evening and early morning and you'll meet the bite. Throw a crawler harness on bottom bouncer or a deep crankbait (trolled) until the fish tell you otherwise.

Season	Depth	Best window	Start at	Go-to baits
Spring	4 to 15 ft	dusk & dawn	Main-lake point (19 ft)	1/8 oz jig + minnow, Hair jig
Summer	15 to 35 ft	dusk & dawn	Main-lake point (19 ft)	Crawler harness on bottom bouncer, Deep crankbait (trolled)
Fall	12 to 40 ft	dusk & night	Break off the point (41 ft)	Jigging rap, Jig + big minnow
Winter	20 to 40 ft	dusk & dawn	Break off the point (41 ft)	Jigging spoon + minnow head, Rattle bait

Northern Pike fishing at Fatty Lake

Spring northern pike on Fatty Lake hold shallow, usually 2 to 8 ft. They move out to 8 to 20 ft in summer and finish the year down in 5 to 15 ft. Put Shallow bay flat first on the milk run — a weed flat near 6 ft that grades prime for spring. The feeding windows run early morning and the evening. The summer box starts with a bucktail or a weedless spoon over cabbage.

Season	Depth	Best window	Start at	Go-to baits
Spring	2 to 8 ft	midday & dawn	Shallow bay flat (6 ft)	#5 inline spinner, Spoon (red/white)
Summer	8 to 20 ft	dawn & dusk	Shallow bay flat (6 ft)	Bucktail, Weedless spoon over cabbage
Fall	6 to 18 ft	midday & dawn	Shallow bay flat (6 ft)	Big rubber (Bull Dawg style), Husky-style jerkbait
Winter	5 to 15 ft	midday	Shallow bay flat (6 ft)	Tip-ups, Large jigging spoon

Yellow Perch fishing at Fatty Lake

Spring puts yellow perch in skinny water — 3 to 12 ft is the zone. Warm water sends them out to 10 to 30 ft; cold water stacks them in 15 to 35 ft. Shallow bay flat is the standout, a weed flat at roughly 6 ft, rated prime for spring yellow perch. Plan around early morning in the warm months. A drop-shot micro plastics or a small spoon tipped with worm covers the summer program.

Season	Depth	Best window	Start at	Go-to baits
Spring	3 to 12 ft	midday & dawn	Shallow bay flat (6 ft)	Small jig + curly tail, Perch-pattern micro crank
Summer	10 to 30 ft	dawn	Shallow bay flat (6 ft)	Drop-shot micro plastics, Small spoon tipped with worm
Fall	12 to 35 ft	midday	Break off the point (41 ft)	Jigging spoon (small), Perch rig / spreader
Winter	15 to 35 ft	midday & dawn	Deep basin (58 ft)	Tungsten jig + spikes, Rattle spoon (small)

Smallmouth Bass fishing at Fatty Lake

Spring smallmouth bass on Fatty Lake hold shallow, usually 3 to 12 ft. They move out to 10 to 30 ft in summer and finish the year down in 20 to 45 ft. Put Main-lake point first on the milk run — a point near 19 ft that grades prime for fall. The feeding windows run early morning and the evening. The summer box starts with a drop shot (goby/minnow) or a ned rig.

Season	Depth	Best window	Start at	Go-to baits
Spring	3 to 12 ft	dawn & dusk	open water	Ned rig, Tube jig
Summer	10 to 30 ft	dawn & dusk	Main-lake point (19 ft)	Drop shot (goby/minnow), Ned rig
Fall	8 to 25 ft	midday & dawn	Main-lake point (19 ft)	Jerkbait, Blade bait
Winter	20 to 45 ft	midday	Break off the point (41 ft)	Blade bait, Hair jig

Rainbow Trout fishing at Fatty Lake

Come spring, look for rainbow trout tight to the bank in 5 to 20 ft. Expect a summer slide to 8 to 30 ft, then a winter hold in 8 to 40 ft. Start at Break off the point. It's a drop-off holding about 41 ft of water and rates prime come winter. Prime time lands in early morning and the evening. A dodger + spoon (deep troll) or a flutter spoon is the honest summer answer here.

Season	Depth	Best window	Start at	Go-to baits
Spring	5 to 20 ft	dawn & dusk	Main-lake point (19 ft)	Inline spinner (silver), Small spoon
Summer	8 to 30 ft	dawn & dusk	Main-lake point (19 ft)	Dodger + spoon (deep troll), Flutter spoon
Fall	10 to 35 ft	dawn & dusk	Main-lake point (19 ft)	Casting spoon, Jerkbait over shoals
Winter	8 to 40 ft	dawn	Break off the point (41 ft)	Jigging spoon, Tube jig (white)

Lake Trout fishing at Fatty Lake

Early season lake trout use the shallows, holding in 10 to 40 ft. Expect a summer slide to 18 to 60 ft, then a winter hold in 15 to 60 ft. Put Deep basin first on the milk run — a deep basin near 58 ft that grades prime for summer. In summer the feeding windows fall in early morning. Tie on a white tube jig (deep) or a magnum spoon on downrigger and you're in the game.

Season	Depth	Best window	Start at	Go-to baits
Spring	10 to 40 ft	dawn & dusk	Main-lake point (19 ft)	Casting spoon over shoals, Jerkbait (shallow)
Summer	18 to 60 ft	dawn	Deep basin (58 ft)	White tube jig (deep), Magnum spoon on downrigger
Fall	10 to 50 ft	dusk & dawn	Main-lake point (19 ft)	Heavy casting spoon, Jigging rap over reefs
Winter	15 to 60 ft	dawn	Deep basin (58 ft)	White tube jig, Airplane jig

Fatty Lake also holds crappie (10 to 25 ft in summer), channel catfish (8 to 25 ft in summer). Pick any of them on the map above for rated spots and bait picks.

Notable structure

Structure-wise the chart holds 4 features, led in depth by Deep basin at roughly 58 ft.

Deep basin: deep basin, around 58 ft
Break off the point: drop-off, around 41 ft
Main-lake point: point, around 19 ft
Shallow bay flat: weed flat, around 6 ft

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

Check the official Montana fishing regulations →

Common questions

How deep is Fatty Lake?

Fatty Lake is about 60 ft (18 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 Fatty Lake?

Anglers target walleye, northern pike, yellow perch, smallmouth bass, rainbow trout, lake trout, crappie, channel catfish on Fatty Lake. This isn't a survey of the water — none is published for it — but an informed estimate from the species common to the region, narrowed by this water's depth, size and each species' range.

Where is the best fishing spot on Fatty Lake?

Shallow bay flat is the top-rated area: a weed flat in about 6 ft of water that rates prime for northern pike in spring. Every other rated spot, per species and season, is on the map above.

When is the best time to fish Fatty Lake?

For walleye, 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 Fatty Lake?

Fishing on Fatty 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

Shay Lake 5 mi · Van Lake 8 mi · Fran Lake 11 mi · Sunburst Lake 15 mi · Jette Lake 15 mi · Palisade Lake 17 mi · Flathead Lake 17 mi · Swan Lake 19 mi · Mcdonald Lake 19 mi · Rubble Lake 21 mi · Woodward Lake 22 mi · Horseshoe Lake (Lake) 23 mi

See how Fatty Lake stacks up: best smallmouth bass lakes in Montana · best walleye lakes in Montana · best northern pike lakes in Montana · best crappie lakes in Montana

More water nearby: Lake County fishing maps (12 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.