Rainbow Lake (Beaverhead) 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 Rainbow Lake (Beaverhead)

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 Rainbow Lake (Beaverhead) on the board.

Fishing Rainbow Lake (Beaverhead): what the data says

10-acre lake in Beaverhead County, Montana. The lake tops out around 33 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. Here's the year, species by species, as the scoring engine sees it.

The drawn water covers 10 acres wrapped in 0.5 miles of bank. At index 1 the outline is almost a bowl — read the depth changes, not the shoreline. 36% of the surface is littoral (under ~15 ft) — cover, weeds and forage water. Beaverhead County claims this one. Lake Agnes sits 2 mi east — the closest neighbouring chart.

Walleye fishing at Rainbow Lake (Beaverhead)

The spring pattern is a shallow one: walleye in 4 to 15 ft. As the season builds they drop to 10 to 33 ft, wintering in 10 to 33 ft. Top water on the chart: Shoreline break, a drop-off in the 20 ft range, prime in fall. Time it for the evening and early morning. 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	open water	1/8 oz jig + minnow, Hair jig
Summer	10 to 33 ft	dusk & dawn	Shoreline break (20 ft)	Crawler harness on bottom bouncer, Deep crankbait (trolled)
Fall	10 to 33 ft	dusk & night	Shoreline break (20 ft)	Jigging rap, Jig + big minnow
Winter	10 to 33 ft	dusk & dawn	Deep basin (33 ft)	Jigging spoon + minnow head, Rattle bait

Northern Pike fishing at Rainbow Lake (Beaverhead)

Early season northern pike use the shallows, holding in 2 to 8 ft. Expect a summer slide to 8 to 20 ft, then a winter hold in 5 to 15 ft. Put Shallow bay flat first on the milk run — a weed flat near 10 ft that grades prime for winter. In summer the feeding windows fall in 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 (10 ft)	#5 inline spinner, Spoon (red/white)
Summer	8 to 20 ft	dawn & dusk	Shallow bay flat (10 ft)	Bucktail, Weedless spoon over cabbage
Fall	6 to 18 ft	midday & dawn	Shallow bay flat (10 ft)	Big rubber (Bull Dawg style), Husky-style jerkbait
Winter	5 to 15 ft	midday	Shallow bay flat (10 ft)	Tip-ups, Large jigging spoon

Yellow Perch fishing at Rainbow Lake (Beaverhead)

In spring, yellow perch run shallow here, mostly 3 to 12 ft. Summer pushes them deeper, 10 to 30 ft, and winter fish settle into 10 to 33 ft. Shallow bay flat is the standout, a weed flat at roughly 10 ft, rated prime for spring yellow perch. Time it for early morning. 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 (10 ft)	Small jig + curly tail, Perch-pattern micro crank
Summer	10 to 30 ft	dawn	Shoreline break (20 ft)	Drop-shot micro plastics, Small spoon tipped with worm
Fall	10 to 33 ft	midday	Deep basin (33 ft)	Jigging spoon (small), Perch rig / spreader
Winter	10 to 33 ft	midday & dawn	Deep basin (33 ft)	Tungsten jig + spikes, Rattle spoon (small)

Smallmouth Bass fishing at Rainbow Lake (Beaverhead)

Early season smallmouth bass use the shallows, holding in 3 to 12 ft. Expect a summer slide to 10 to 30 ft, then a winter hold in 10 to 33 ft. Put Shoreline break first on the milk run — a drop-off near 20 ft that grades prime for winter. In summer the feeding windows fall in 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	open water	Ned rig, Tube jig
Summer	10 to 30 ft	dawn & dusk	Shoreline break (20 ft)	Drop shot (goby/minnow), Ned rig
Fall	8 to 25 ft	midday & dawn	Shoreline break (20 ft)	Jerkbait, Blade bait
Winter	10 to 33 ft	midday	Shoreline break (20 ft)	Blade bait, Hair jig

Rainbow Trout fishing at Rainbow Lake (Beaverhead)

When the water first warms, rainbow trout slide up into 5 to 20 ft. Summer is an 8 to 30 ft game here, winter a 7 to 33 ft one. Start at Shoreline break. It's a drop-off holding about 20 ft of water and rates prime come winter. The feeding windows run 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	Shoreline break (20 ft)	Inline spinner (silver), Small spoon
Summer	8 to 30 ft	dawn & dusk	Shoreline break (20 ft)	Dodger + spoon (deep troll), Flutter spoon
Fall	9 to 33 ft	dawn & dusk	Shoreline break (20 ft)	Casting spoon, Jerkbait over shoals
Winter	7 to 33 ft	dawn	Shoreline break (20 ft)	Jigging spoon, Tube jig (white)

Lake Trout fishing at Rainbow Lake (Beaverhead)

Spring lake trout on Rainbow Lake (Beaverhead) hold shallow, usually 8 to 33 ft. Depth-wise the year is flat: 10 to 33 ft in summer, 8 to 33 ft once it turns cold. Put Deep basin first on the milk run — a deep basin near 33 ft that grades prime for summer. The feeding windows run 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	8 to 33 ft	dawn & dusk	Shoreline break (20 ft)	Casting spoon over shoals, Jerkbait (shallow)
Summer	10 to 33 ft	dawn	Deep basin (33 ft)	White tube jig (deep), Magnum spoon on downrigger
Fall	7 to 33 ft	dusk & dawn	Shoreline break (20 ft)	Heavy casting spoon, Jigging rap over reefs
Winter	8 to 33 ft	dawn	Deep basin (33 ft)	White tube jig, Airplane jig

Rainbow Lake (Beaverhead) 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 3 features, led in depth by Deep basin at roughly 33 ft.

Deep basin: deep basin, around 33 ft
Shoreline break: drop-off, around 20 ft
Shallow bay flat: weed flat, around 10 ft

Rainbow Lake (Beaverhead) 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 Rainbow Lake (Beaverhead) specifically, so confirm the current rules before you fish.

Check the official Montana fishing regulations →

Common questions

How deep is Rainbow Lake (Beaverhead)?

Rainbow Lake (Beaverhead) is about 33 ft (10 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 Rainbow Lake (Beaverhead)?

Anglers target walleye, northern pike, yellow perch, smallmouth bass, rainbow trout, lake trout, crappie, channel catfish on Rainbow Lake (Beaverhead). 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 Rainbow Lake (Beaverhead)?

Shoreline break is the top-rated area: a drop-off in about 20 ft of water that rates prime for walleye in fall. Open the map above to see every rated spot for each species and season.

When is the best time to fish Rainbow Lake (Beaverhead)?

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 Rainbow Lake (Beaverhead)?

Fishing on Rainbow Lake (Beaverhead) 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

Lake Agnes 2 mi · Brownes Lake 3 mi · Tendoy Lake 4 mi · Deerhead Lake 6 mi · Sawtooth Lake 10 mi · Minneopa Lake 10 mi · Kelly Reservioir 13 mi · Bear Lake (Beaverhead) 18 mi · Baldy Lake 20 mi · Sand Lake 21 mi · Beaverhead River 21 mi · Lily Lake (Beaverhead) 23 mi

See how Rainbow Lake (Beaverhead) 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: Beaverhead County fishing maps (24 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.