Lake Otatsy 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 Lake Otatsy

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 Lake Otatsy on the board.

Fishing Lake Otatsy: what the data says

19-acre lake in Powell County, Montana. The lake tops out around 30 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.

The outline encloses 23 acres, worked by 0.9 miles of shoreline. The basin is a simple one (shoreline index 1.4) — close to a bowl, so the structure on the chart matters more than the bank. 54% of the surface is littoral (under ~15 ft) — cover, weeds and forage water. Call it 0.4 mi long. It sits in Powell County. If the bite dies, Camp Lake (Lewis and Clark) is 1 mi to the northwest.

Rainbow Trout fishing at Lake Otatsy

Spring rainbow trout on Lake Otatsy hold shallow, usually 5 to 20 ft. By summer they slide out to 8 to 30 ft, and by winter most fish are in 6 to 30 ft. The chart's best answer is Break off the point — drop-off, 18 ft, prime for winter. Prime time lands in early morning and the evening. The summer box starts with a dodger + spoon (deep troll) or a flutter spoon.

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 (18 ft)	Dodger + spoon (deep troll), Flutter spoon
Fall	9 to 30 ft	dawn & dusk	Main-lake point (11 ft)	Casting spoon, Jerkbait over shoals
Winter	6 to 30 ft	dawn	Break off the point (18 ft)	Jigging spoon, Tube jig (white)

Notable structure

Lake Otatsy carries 4 mapped structure features, topping out (or rather bottoming out) at Deep basin, about 30 ft down.

Deep basin: deep basin, around 30 ft
Break off the point: drop-off, around 18 ft
Main-lake point: point, around 11 ft
Shallow bay flat: weed flat, around 3 ft

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

Check the official Montana fishing regulations →

Common questions

How deep is Lake Otatsy?

Lake Otatsy is about 30 ft (9 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 Lake Otatsy?

Anglers target rainbow trout on Lake Otatsy.

Where is the best fishing spot on Lake Otatsy?

Break off the point is the top-rated area: a drop-off in about 18 ft of water that rates prime for rainbow trout in winter. Every other rated spot, per species and season, is on the map above.

When is the best time to fish Lake Otatsy?

For rainbow 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 Lake Otatsy?

Fishing on Lake Otatsy 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

Camp Lake (Lewis and Clark) 1 mi · Canyon Lake (Lewis and Clark) 1 mi · Coopers Lake 8 mi · Upsata Lake 11 mi · Parker Lake 14 mi · Cottonwood Lake, Middle 15 mi · Browns Lake 15 mi · Blackfoot River 16 mi · Pyramid Lake 18 mi · Heart Lake (Lewis and Clark) 18 mi · Salmon Lake 19 mi · Harpers Lake 20 mi

See how Lake Otatsy stacks up: best rainbow trout lakes in Montana

More water nearby: Powell County fishing maps (8 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.