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266-acre lake in Carbon County, Montana. The lake tops out around 140 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 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 Main-lake point, a point in about 1 ft of water that rates good for walleye in fall. 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 (1 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Break off the point (77 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Main-lake point (1 ft) | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | Deep basin (138 ft) | Jigging spoon + minnow head, Rattle bait |
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 — feeding flat, 1 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 (1 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | open water | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Break off the point (77 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. 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 feeding flat around 1 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 (1 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Deep basin (138 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Deep basin (138 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Deep basin (138 ft) | Tungsten jig + spikes, Rattle spoon (small) |
Early season smallmouth bass use the shallows, holding in 3 to 12 ft. Summer is a 10 to 30 ft game here, winter a 20 to 45 ft one. The chart's best answer is Main-lake point — point, 1 ft, good for spring. 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 (1 ft) | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Break off the point (77 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Main-lake point (1 ft) | Jerkbait, Blade bait |
| Winter | 20 to 45 ft | midday | Break off the point (77 ft) | Blade bait, Hair jig |
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 Main-lake point: a point around 1 ft that scores good in spring. 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 (1 ft) | Inline spinner (silver), Small spoon |
| Summer | 8 to 30 ft | dawn & dusk | open water | Dodger + spoon (deep troll), Flutter spoon |
| Fall | 10 to 35 ft | dawn & dusk | Main-lake point (1 ft) | Casting spoon, Jerkbait over shoals |
| Winter | 8 to 40 ft | dawn | Break off the point (77 ft) | Jigging spoon, Tube jig (white) |
Spring lake trout on Fossil Lake (Carbon) hold shallow, usually 10 to 40 ft. By summer they slide out to 50 to 120 ft, and by winter most fish are in 20 to 80 ft. The chart's best answer is Break off the point — drop-off, 77 ft, prime for winter. 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 (1 ft) | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 50 to 120 ft | dawn | Break off the point (77 ft) | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | Main-lake point (1 ft) | Heavy casting spoon, Jigging rap over reefs |
| Winter | 20 to 80 ft | dawn | Break off the point (77 ft) | White tube jig, Airplane jig |
Fossil Lake (Carbon) 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.
Fossil Lake (Carbon) carries 5 mapped structure features, topping out (or rather bottoming out) at Deep basin, about 138 ft down.
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 Fossil Lake (Carbon) specifically, so confirm the current rules before you fish.
Check the official Montana fishing regulations →
Fossil Lake (Carbon) is about 140 ft (43 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 Fossil Lake (Carbon). 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 77 ft of water that rates prime for lake trout in winter. Open the map above to see every rated spot for each 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 Fossil Lake (Carbon) 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.
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More water nearby: Carbon County fishing maps (65 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.