Frank 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 Frank 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 Frank Lake on the board.

Fishing Frank Lake: what the data says

155-acre lake in Lincoln County, Montana. The lake tops out around 40 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. What the data behind the map says about each species, season by season:

Frank Lake maps at 155 acres behind 2.7 miles of shoreline. A middling shoreline index (1.5) gives it some bays to work without being a maze. About 67% of the surface sits shallower than 15 ft — that's the weed-and-bait zone. End to end it runs roughly 1.2 mi, about 0.3 mi across. It sits in Lincoln County. Its nearest charted neighbour, Long Lake (Lincoln), is 1 mi to the north.

Walleye fishing at Frank Lake

The spring pattern is a shallow one: walleye in 4 to 15 ft. Midsummer fish sit out in 15 to 35 ft before dropping to 20 to 40 ft for winter. The spot to know is Deep basin, a deep basin in about 40 ft of water that rates prime for walleye in winter. Plan around the evening and early morning in the warm months. Summer baits: a crawler harness on bottom bouncer or a deep crankbait (trolled) gets it done.

Season	Depth	Best window	Start at	Go-to baits
Spring	4 to 15 ft	dusk & dawn	Main-lake point (11 ft)	1/8 oz jig + minnow, Hair jig
Summer	15 to 35 ft	dusk & dawn	Break off the point (10 ft)	Crawler harness on bottom bouncer, Deep crankbait (trolled)
Fall	12 to 40 ft	dusk & night	Break off the point (10 ft)	Jigging rap, Jig + big minnow
Winter	20 to 40 ft	dusk & dawn	Deep basin (40 ft)	Jigging spoon + minnow head, Rattle bait

Northern Pike fishing at Frank Lake

Early season northern pike use the shallows, holding in 2 to 8 ft. Summer is an 8 to 20 ft game here, winter a 5 to 15 ft one. The chart's best answer is Shallow bay flat — weed flat, 5 ft, prime for spring. Best bite is early morning and the evening. Tie on a bucktail or a weedless spoon over cabbage and you're in the game.

Season	Depth	Best window	Start at	Go-to baits
Spring	2 to 8 ft	midday & dawn	Shallow bay flat (5 ft)	#5 inline spinner, Spoon (red/white)
Summer	8 to 20 ft	dawn & dusk	Break off the point (10 ft)	Bucktail, Weedless spoon over cabbage
Fall	6 to 18 ft	midday & dawn	Break off the point (10 ft)	Big rubber (Bull Dawg style), Husky-style jerkbait
Winter	5 to 15 ft	midday	Shallow bay flat (5 ft)	Tip-ups, Large jigging spoon

Yellow Perch fishing at Frank Lake

In spring, yellow perch run shallow here, mostly 3 to 12 ft. Midsummer fish sit out in 10 to 30 ft before dropping to 15 to 35 ft for winter. Spring yellow perch concentrate at Shallow bay flat, a prime-rated weed flat around 5 ft. Fish it in early morning and you'll meet the bite. You won't need more than a drop-shot micro plastics or a small spoon tipped with worm most summer days.

Season	Depth	Best window	Start at	Go-to baits
Spring	3 to 12 ft	midday & dawn	Shallow bay flat (5 ft)	Small jig + curly tail, Perch-pattern micro crank
Summer	10 to 30 ft	dawn	Break off the point (10 ft)	Drop-shot micro plastics, Small spoon tipped with worm
Fall	12 to 35 ft	midday	Break off the point (10 ft)	Jigging spoon (small), Perch rig / spreader
Winter	15 to 35 ft	midday & dawn	Deep basin (40 ft)	Tungsten jig + spikes, Rattle spoon (small)

Smallmouth Bass fishing at Frank Lake

Early season smallmouth bass use the shallows, holding in 3 to 12 ft. Summer is a 10 to 30 ft game here, winter a 12 to 40 ft one. The chart's best answer is Main-lake point — point, 11 ft, prime for fall. Best bite is early morning and the evening. Tie on a drop shot (goby/minnow) or a ned rig and you're in the game.

Season	Depth	Best window	Start at	Go-to baits
Spring	3 to 12 ft	dawn & dusk	Main-lake point (11 ft)	Ned rig, Tube jig
Summer	10 to 30 ft	dawn & dusk	Break off the point (10 ft)	Drop shot (goby/minnow), Ned rig
Fall	8 to 25 ft	midday & dawn	Main-lake point (11 ft)	Jerkbait, Blade bait
Winter	12 to 40 ft	midday	Break off the point (10 ft)	Blade bait, Hair jig

Rainbow Trout fishing at Frank Lake

When the water first warms, rainbow trout slide up into 5 to 20 ft. By summer they slide out to 8 to 30 ft, and by winter most fish are in 8 to 40 ft. If you only fish one area, make it Break off the point: a drop-off around 10 ft that scores prime in winter. In summer the feeding windows fall in early morning and the evening. Keep a dodger + spoon (deep troll) or a flutter spoon rigged through the warm months.

Season	Depth	Best window	Start at	Go-to baits
Spring	5 to 20 ft	dawn & dusk	Main-lake point (11 ft)	Inline spinner (silver), Small spoon
Summer	8 to 30 ft	dawn & dusk	Break off the point (10 ft)	Dodger + spoon (deep troll), Flutter spoon
Fall	10 to 35 ft	dawn & dusk	Main-lake point (11 ft)	Casting spoon, Jerkbait over shoals
Winter	8 to 40 ft	dawn	Break off the point (10 ft)	Jigging spoon, Tube jig (white)

Lake Trout fishing at Frank Lake

Spring lake trout on Frank Lake hold shallow, usually 10 to 40 ft. Depth-wise the year is flat: 12 to 40 ft in summer, 10 to 40 ft once it turns cold. The chart's best answer is Deep basin — deep basin, 40 ft, prime for summer. Prime time lands in early morning. The summer box starts with a white tube jig (deep) or a magnum spoon on downrigger.

Season	Depth	Best window	Start at	Go-to baits
Spring	10 to 40 ft	dawn & dusk	Main-lake point (11 ft)	Casting spoon over shoals, Jerkbait (shallow)
Summer	12 to 40 ft	dawn	Deep basin (40 ft)	White tube jig (deep), Magnum spoon on downrigger
Fall	8 to 40 ft	dusk & dawn	Main-lake point (11 ft)	Heavy casting spoon, Jigging rap over reefs
Winter	10 to 40 ft	dawn	Deep basin (40 ft)	White tube jig, Airplane jig

Frank 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

5 pieces of structure are mapped here — Deep basin, around 40 ft, is the deepest of them.

Deep basin: deep basin, around 40 ft
Main-lake point: point, around 11 ft
Break off the point: drop-off, around 10 ft
Secondary point: point, around 6 ft
Shallow bay flat: weed flat, around 5 ft

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

Check the official Montana fishing regulations →

Common questions

How deep is Frank Lake?

Frank Lake is about 40 ft (12 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 Frank Lake?

Anglers target walleye, northern pike, yellow perch, smallmouth bass, rainbow trout, lake trout, crappie, channel catfish on Frank 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 Frank Lake?

Deep basin is the top-rated area: a deep basin in about 40 ft of water that rates prime for walleye in winter. Scroll up to the map for the complete spot list by species and season.

When is the best time to fish Frank 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 Frank Lake?

Fishing on Frank 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

Long Lake (Lincoln) 1 mi · Rock Lake 2 mi · Glen Lake 5 mi · Murphy Lake 8 mi · Martin Lake (Lincoln) 9 mi · Dickey Lake (Lincoln) 11 mi · BIG THERRIAULT LAKE 11 mi · Little Therriault Lake 11 mi · Tetrault Lake 11 mi · Moran Lake 12 mi · Sophie Lake 12 mi · Blue Lake (Flathead) 15 mi

See how Frank 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: Lincoln County fishing maps (28 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.