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Rating depth structure for lake trout.
Shared by DepthScout anglers. Exact spots stay private, always.
1,847-acre lake near TA R10 WELS. The lake tops out around 72 ft. The depth chart comes from published agency bathymetric survey data, so the contours are survey-derived rather than computer-modeled. Here is how the season plays out for each species, straight from the data behind the map.
Traced from the shoreline, Upper Jo-Mary Lake runs 1,846 acres with 12.8 miles of edge — 13 islands included. The shoreline is moderately structured (index 2.1) — enough points and pockets to pattern. About 21% of the surface sits shallower than 15 ft — that's the weed-and-bait zone. Call it 3 mi long by 1.7 mi wide at the broadest reach. You'll find it in Piscataquis County. The nearest mapped water is Cedar Pond, 4 mi to the southwest.
Spring puts brook trout in skinny water — 2 to 15 ft is the zone. As the season builds they drop to 10 to 30 ft, wintering in 3 to 20 ft. Spring brook trout concentrate at Duck Brook inflow, a prime-rated inflow / creek mouth around 7 ft. Warm-month bites cluster around early morning and the evening. A small spoon fished deep or a trolled lake-clear wobbler + worm covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 15 ft | dawn & dusk | Duck Brook inflow (7 ft) | Small inline spinner (gold), Tiny spoon |
| Summer | 10 to 30 ft | dawn & dusk | Duck Brook inflow (7 ft) | Small spoon fished deep, Trolled lake-clear wobbler + worm |
| Fall | 2 to 15 ft | midday & dawn | Duck Brook inflow (7 ft) | Small spoon (orange), Spinner |
| Winter | 3 to 20 ft | dawn | Duck Brook inflow (7 ft) | Small jigging spoon, Tungsten jig + plastic |
In spring, landlocked salmon run shallow here, mostly 1 to 15 ft. Summer pushes them deeper, 25 to 60 ft, and winter fish settle into 10 to 40 ft. Duck Brook inflow is the standout, an inflow / creek mouth at roughly 7 ft, rated prime for spring landlocked salmon. Time it for early morning and the evening. You won't need more than a dodger + streamer down deep or a thin spoon on lead core most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 1 to 15 ft | dawn & dusk | Duck Brook inflow (7 ft) | Streamer flies (Grey Ghost) off boards, Thin spoon (Mooselook style) |
| Summer | 25 to 60 ft | dawn & dusk | Break off the point (42 ft) | Dodger + streamer down deep, Thin spoon on lead core |
| Fall | 5 to 30 ft | dawn & dusk | Duck Brook inflow (7 ft) | Casting spoon at the mouths, Streamers |
| Winter | 10 to 40 ft | dawn | Break off the point (42 ft) | Small jigging spoon, Swedish pimple + smelt |
Spring puts brown bullhead in skinny water — 2 to 8 ft is the zone. Warm water sends them out to 3 to 12 ft; cold water stacks them in 10 to 25 ft. Shallow bay flat is the standout, a weed flat at roughly 3 ft, rated prime for spring brown bullhead. Plan around after dark and the evening in the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | dusk & night | Shallow bay flat (3 ft) | |
| Summer | 3 to 12 ft | night & dusk | Shallow bay flat (3 ft) | |
| Fall | 5 to 15 ft | dusk | Back-bay flat (6 ft) | |
| Winter | 10 to 25 ft | midday | Deep basin (70 ft) |
Come spring, look for chain pickerel tight to the bank in 2 to 10 ft. They move out to 3 to 15 ft in summer and finish the year down in 5 to 18 ft. If you only fish one area, make it Shallow bay flat: a weed flat around 3 ft that scores prime in spring. Best bite is early morning and the evening. A weedless spoon + trailer or a buzzbait is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 10 ft | midday & dawn | Shallow bay flat (3 ft) | Inline spinner (silver), Small spoon (red/white) |
| Summer | 3 to 15 ft | dawn & dusk | Shallow bay flat (3 ft) | Weedless spoon + trailer, Buzzbait |
| Fall | 4 to 15 ft | midday & dawn | Back-bay flat (6 ft) | Jerkbait along weed edges, Spinnerbait |
| Winter | 5 to 18 ft | dawn | Back-bay flat (6 ft) | Jigging spoon (through ice) |
In spring, burbot run shallow here, mostly 25 to 70 ft. Midsummer fish sit out in 22 to 72 ft before dropping to 15 to 60 ft for winter. Spring burbot concentrate at Deep basin, a prime-rated deep basin around 70 ft. Fish it in after dark and midday and you'll meet the bite. You won't need more than a heavy jig + cut bait most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 25 to 70 ft | night & dusk | Deep basin (70 ft) | Glow jigging spoon + cut bait, Rattle bait (dark) |
| Summer | 22 to 72 ft | night & midday | Deep basin (70 ft) | Heavy jig + cut bait |
| Fall | 22 to 72 ft | night & dusk | Deep basin (70 ft) | Glow spoon + minnow head, Blade bait (slow) |
| Winter | 15 to 60 ft | night & dusk | Break off the point (42 ft) | Glow tungsten + cut bait, Rattle spoon + minnow head |
In spring, lake trout run shallow here, mostly 10 to 40 ft. Midsummer fish sit out in 22 to 72 ft before dropping to 18 to 72 ft for winter. Summer lake trout concentrate at Deep basin, a prime-rated deep basin around 70 ft. Fish it in early morning and you'll meet the bite. You won't need more than a white tube jig (deep) or a magnum spoon on downrigger most summer days.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | Secondary point (7 ft) | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 22 to 72 ft | dawn | Deep basin (70 ft) | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | Secondary point (7 ft) | Heavy casting spoon, Jigging rap over reefs |
| Winter | 18 to 72 ft | dawn | Deep basin (70 ft) | White tube jig, Airplane jig |
10 pieces of structure are mapped here — Deep basin, around 70 ft, is the deepest of them.
| Date | Species | Count | Size |
|---|---|---|---|
| May 28 | Landlocked Salmon | 800 | ~7" |
| May 13 | Brook Trout | 1,800 | ~10" |
Source: Maine IFW stocking report, retrieved 2026-08-18.
Season dates, license requirements, and size and bag limits for Maine waters are set by the Maine IFW — and special regulations can apply to Upper Jo-Mary Lake specifically, so confirm the current rules before you fish.
Check the official Maine fishing regulations →
Upper Jo-Mary Lake is about 72 ft (22 m) deep at its deepest point. The depth chart comes from published agency bathymetric survey data, so the contours are survey-derived rather than computer-modeled.
Anglers target brook trout, landlocked salmon, brown bullhead, chain pickerel, burbot, lake trout on Upper Jo-Mary Lake.
Duck Brook inflow is the top-rated area: an inflow / creek mouth in about 7 ft of water that rates prime for brook trout in spring. Scroll up to the map for the complete spot list by species and season.
For brook 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.
Yes — per Maine IFW stocking report records, Upper Jo-Mary Lake was most recently stocked May 28 with 800 landlocked salmon. The full stocking history is listed above.
Fishing on Upper Jo-Mary Lake is regulated by the Maine IFW. Check the official Maine regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Cedar Pond 4 mi · Lower Jo-Mary Lake 5 mi · Johnston Pond 5 mi · Church Pond 5 mi · Gauntlet Pond 6 mi · Pemadumcook Lake 7 mi · Henderson Pond 8 mi · B Pond 8 mi · Round Pond 9 mi · Tumbledown Dick Pond 9 mi · Cedar Lake 9 mi · Big Rocky Pond 9 mi
See how Upper Jo-Mary Lake stacks up: best lake trout lakes in Maine · best brook trout lakes in Maine · best landlocked salmon lakes in Maine · best chain pickerel lakes in Maine
More water nearby: Piscataquis County fishing maps (191 charts). Browse all Maine fishing maps or see every water on DepthScout. Bathymetry: published agency survey data. 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.