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327-acre reservoir in Lake County, Montana. The lake tops out around 70 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 spring pattern is a shallow one: walleye in 4 to 15 ft. As the season builds they drop to 15 to 35 ft, wintering in 20 to 40 ft. Top water on the chart: Break off the point, a drop-off in the 29 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 | Main-lake point (1 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Break off the point (29 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Break off the point (29 ft) | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | Break off the point (29 ft) | Jigging spoon + minnow head, Rattle bait |
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 1 ft that grades prime for spring. 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 (1 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Shallow bay flat (1 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Shallow bay flat (1 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow bay flat (1 ft) | Tip-ups, Large jigging spoon |
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 15 to 35 ft. Break off the point is the standout, a drop-off at roughly 29 ft, rated prime for summer 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 (1 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Break off the point (29 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Break off the point (29 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Break off the point (29 ft) | Tungsten jig + spikes, Rattle spoon (small) |
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 20 to 45 ft. Put Break off the point first on the milk run — a drop-off near 29 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 | Main-lake point (1 ft) | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Break off the point (29 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Break off the point (29 ft) | Jerkbait, Blade bait |
| Winter | 20 to 45 ft | midday | Break off the point (29 ft) | Blade bait, Hair jig |
When the water first warms, rainbow trout slide up into 5 to 20 ft. Summer is an 8 to 30 ft game here, winter an 8 to 40 ft one. Start at Break off the point. It's a drop-off holding about 29 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 | Main-lake point (1 ft) | Inline spinner (silver), Small spoon |
| Summer | 8 to 30 ft | dawn & dusk | Break off the point (29 ft) | Dodger + spoon (deep troll), Flutter spoon |
| Fall | 10 to 35 ft | dawn & dusk | Break off the point (29 ft) | Casting spoon, Jerkbait over shoals |
| Winter | 8 to 40 ft | dawn | Break off the point (29 ft) | Jigging spoon, Tube jig (white) |
Spring lake trout on Mission Reservoir, In Part hold shallow, usually 10 to 40 ft. They move out to 21 to 70 ft in summer and finish the year down in 18 to 70 ft. Put Deep basin first on the milk run — a deep basin near 63 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 | 10 to 40 ft | dawn & dusk | Break off the point (29 ft) | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 21 to 70 ft | dawn | Deep basin (63 ft) | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | Break off the point (29 ft) | Heavy casting spoon, Jigging rap over reefs |
| Winter | 18 to 70 ft | dawn | Deep basin (63 ft) | White tube jig, Airplane jig |
Mission Reservoir, In Part 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.
Structure-wise the chart holds 6 features, led in depth by Deep basin at roughly 63 ft.
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 Mission Reservoir, In Part specifically, so confirm the current rules before you fish.
Check the official Montana fishing regulations →
Mission Reservoir, In Part is about 70 ft (21 m) deep at its deepest point. The depth chart here comes from real state fisheries GPS surveys, so the contours reflect measured depths.
Anglers target walleye, northern pike, yellow perch, smallmouth bass, rainbow trout, lake trout, crappie, channel catfish on Mission Reservoir, In Part. 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.
Break off the point is the top-rated area: a drop-off in about 29 ft of water that rates prime for walleye in fall. Scroll up to the map for the complete spot list by species and season.
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.
Fishing on Mission Reservoir, In Part 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.
St Marys Lake 6 mi · Mcdonald Lake 7 mi · South Meadow Lake 12 mi · Lindbergh Lake 14 mi · Lake Elsina 15 mi · Rattlesnake Lake #22 16 mi · Colt Lake 16 mi · Lake Marshall 17 mi · Fly Lake (Missoula) 18 mi · Sanders Lake 18 mi · Summit Lake (Missoula) 18 mi · Pierce Lake 19 mi
See how Mission Reservoir, In Part 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.