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Rating depth structure for largemouth bass.
Recent public catches load as you reach this section.
213-acre lake near Oscoda County. The lake tops out around 10 ft. The depth chart comes from published agency bathymetric survey data, so the contours are survey-derived rather than computer-modeled. The season-by-season read for each species follows, from the map's own numbers.
Traced from the shoreline, Shamrock Lake runs 235 acres with 2.6 miles of edge. Its 1.2 shoreline index means few bank features; the contours below do the pattern work. The whole water is littoral — nothing here runs deeper than ~15 ft, so it's all weed-and-bait territory. The basin spans about 1 mi end to end and 0.6 mi across at its widest. You'll find it in Oscoda County. For a second option, McCollum Lake lies 3 mi northeast.
Come spring, look for yellow perch tight to the bank in 3 to 10 ft. Through summer count on 3 to 10 ft; the winter hold is 3 to 10 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. A drop-shot micro plastics or a small spoon tipped with worm is the honest summer answer here.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 10 ft chart-limited; documented 3 to 12 ft | midday & dawn | Shallow bay flat (3 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 3 to 10 ft chart-limited; documented 10 to 30 ft | dawn | Deep basin (10 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 3 to 10 ft chart-limited; documented 12 to 35 ft | midday | Deep basin (10 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 3 to 10 ft chart-limited; documented 15 to 35 ft | midday & dawn | Deep basin (10 ft) | Tungsten jig + spikes, Rattle spoon (small) |
Start shallow in spring: smallmouth bass sit in 3 to 10 ft that time of year. They don't go far with the seasons — 3 to 10 ft covers summer, 3 to 10 ft covers winter. Top water on the chart: Main-lake point, a point in the 5 ft range, prime in fall. Fish it in early morning and the evening and you'll meet the bite. Throw a drop shot (goby/minnow) or a ned rig until the fish tell you otherwise.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 10 ft chart-limited; documented 3 to 12 ft | dawn & dusk | Main-lake point (5 ft) | Ned rig, Tube jig |
| Summer | 3 to 10 ft chart-limited; documented 10 to 30 ft | dawn & dusk | Break off the point (7 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 3 to 10 ft chart-limited; documented 8 to 25 ft | midday & dawn | Main-lake point (5 ft) | Jerkbait, Blade bait |
| Winter | 3 to 10 ft chart-limited; documented 20 to 45 ft | midday | Break off the point (7 ft) | Blade bait, Hair jig |
The spring pattern is a shallow one: largemouth bass in 2 to 10 ft. The depth story barely changes: 3 to 10 ft through summer, 3 to 10 ft in winter. The spot to know is Shallow bay flat, a weed flat in about 3 ft of water that rates prime for largemouth bass in spring. Plan around early morning and the evening in the warm months. Summer baits: a texas-rigged 10" worm or a deep-diving crankbait gets it done.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 10 ft | dawn & dusk | Shallow bay flat (3 ft) | Spinnerbait, Chatterbait |
| Summer | 3 to 10 ft chart-limited; documented 8 to 20 ft | dawn & dusk | Shallow bay flat (3 ft) | Texas-rigged 10" worm, Deep-diving crankbait |
| Fall | 3 to 10 ft chart-limited; documented 4 to 15 ft | midday & dawn | Main-lake point (5 ft) | Squarebill crankbait (shad), Spinnerbait |
| Winter | 3 to 10 ft chart-limited; documented 15 to 35 ft | midday | Break off the point (7 ft) | Blade bait, Jigging spoon |
Start shallow in spring: crappie sit in 2 to 8 ft that time of year. Warm water sends them out to 3 to 10 ft; cold water stacks them in 3 to 10 ft. Top water on the chart: Deep basin, a deep basin in the 10 ft range, prime in winter. Fish it in early morning and the evening and you'll meet the bite. Throw a jig trolled/spider-rigged or a small crankbait (trolled) until the fish tell you otherwise.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (3 ft) | 1/16 oz jig + tube, Curly-tail grub |
| Summer | 3 to 10 ft chart-limited; documented 10 to 25 ft | dawn & dusk | Shallow bay flat (3 ft) | Jig trolled/spider-rigged, Small crankbait (trolled) |
| Fall | 3 to 10 ft chart-limited; documented 8 to 20 ft | dawn | Shallow bay flat (3 ft) | Jig + minnow combo, Small swimbait (1.5-2") |
| Winter | 3 to 10 ft chart-limited; documented 15 to 35 ft | midday | Deep basin (10 ft) | Tungsten jig + soft plastic, Tiny jigging spoon |
In spring, bluegill run shallow here, mostly 1 to 6 ft. Midsummer fish sit out in 3 to 10 ft before dropping to 3 to 10 ft for winter. Spring bluegill concentrate at Shallow bay flat, a prime-rated weed flat around 3 ft. Fish it in early morning and the evening and you'll meet the bite. You won't need more than a small sponge spider (fly) or a micro tube jig most summer days.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 1 to 6 ft | midday & dusk | Shallow bay flat (3 ft) | 1/32 oz jig + micro plastic, Tiny popper (evenings) |
| Summer | 3 to 10 ft chart-limited; documented 4 to 15 ft | dawn & dusk | Shallow bay flat (3 ft) | Small sponge spider (fly), Micro tube jig |
| Fall | 3 to 10 ft chart-limited; documented 6 to 18 ft | midday | Shallow bay flat (3 ft) | Micro jig + waxworm, Small spoon tipped |
| Winter | 3 to 10 ft chart-limited; documented 10 to 25 ft | midday | Deep basin (10 ft) | Tungsten ice jig + plastic, Tiny spoon |
Shamrock Lake carries 6 mapped structure features, topping out (or rather bottoming out) at Deep basin, about 10 ft down.
Season dates, license requirements, and size and bag limits for Michigan waters are set by the Michigan DNR — and special regulations can apply to Shamrock Lake specifically, so confirm the current rules before you fish.
Check the official Michigan fishing regulations →
Shamrock Lake is about 10 ft (3 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 yellow perch, smallmouth bass, largemouth bass, crappie, bluegill on Shamrock Lake. 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.
Shallow bay flat is the top-rated area: a weed flat in about 3 ft of water that rates prime for yellow perch in spring. Scroll up to the map for the complete spot list by species and season.
For yellow perch, the summer bite is best in 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 Shamrock Lake is regulated by the Michigan DNR. Check the official Michigan regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
McCollum Lake 3 mi · Crooked Lake 3 mi · Bass Lake 7 mi · Perry Lake 8 mi · Perry Lake 8 mi · Lockwood Lake 12 mi · Muskrat Lake 15 mi · Sage Lakes 15 mi · Beaver Lake 15 mi · Curtis Lake 15 mi · North Lake 16 mi · Jewell Lake 17 mi
See how Shamrock Lake stacks up: best largemouth bass lakes in Michigan · best smallmouth bass lakes in Michigan · best crappie lakes in Michigan · best bluegill lakes in Michigan
More water nearby: Oscoda County fishing maps (12 charts). Browse all Michigan fishing maps. 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.