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LakeQuality
Two canoes crossing open water between forested points in the Boundary Waters

Updated August 2026

Biggest Inland Lake in Indiana: Monroe Lake (10,750 acres)

Monroe Lake is Indiana's largest inland lake per the Indiana Department of Natural Resources (Division of State Parks). Below: 50 Indiana lakes ranked by surface area.

The largest inland lake in Indiana is Monroe Lake at 10,750 acres , in Monroe County, according to the Indiana Department of Natural Resources (Division of State Parks). Lake Michigan is a Great Lake shared with Michigan, Wisconsin and Illinois. IDEM states Indiana 'can only lay claim to about 1% (224 mi²) of Lake Michigan's area and 45 miles of its shoreline' (https://www.in.gov/idem/lakemichigan/about-lake-michigan/), so it is not treated as an Indiana lake.

See our Monroe Lake water-quality readings —

Source: Indiana Department of Natural Resources (Division of State Parks) (2026-07-30). The table below ranks the Indiana lakes in our own index by surface area.

50
Lakes with area data
4,364
Largest (acres)
356
Median of top 50
4/50
Reservoirs (vs natural)

Reading Indiana's size profile

Indiana's largest lake by surface area is Brookville Lake in Union County, spanning 4,364 acres. Most of Indiana's biggest waters are natural basins left by glaciers, with stable shorelines and deep main basins.

Surface area is a poor proxy for water quality on its own — a large lake can hold a clean, deep core and a nutrient-loaded bay at the same time. Each lake below links to its full page with nutrient readings, clarity, depth, and EPA impairment status. Area figures come from state DNR surveys and the USACE National Inventory of Dams; water-quality readings come from EPA and state monitoring data.

The 50 biggest lakes in Indiana by surface area

#LakeCountySurface areaMax depth
1Brookville LakeUnion4,364 acres-
2Broad PondGibson2,942 acres16.1 ft
3Mississinewa LakeWabash2,160 acres-
4Lake MaxinkuckeeMarshall1,910 acres87.9 ft
5Lake JamesSteuben1,883 acres56.1 ft
6Lake LemonMonroe1,650 acres-
7Turtle Creek LakeSullivan1,558 acres-
8Morse ReservoirHamilton1,440 acres44.9 ft
9Geist ReservoirMarion1,153 acres-
10Hamilton LakeSteuben835 acres69.9 ft
11Greenwood LakeMartin831 acres-
12Colonial PondFulton810 acres44 ft
13Crooked LakeSteuben801 acres85 ft
14Webster LakeKosciusko774 acres-
15J C Murphey LakeNewton754 acres7.9 ft
16Sylvan LakeNoble653 acres29.9 ft
17Lake GeorgeSteuben538 acres-
18Big Turkey LakeSteuben470 acres65 ft
19Waldron LakeNoble429 acres34.1 ft
20Hudson LakeLaPorte427 acres42 ft
21Lake of the WoodMarshall421 acres47.9 ft
22Dallas LakeLaGrange407 acres32.2 ft
23Lake SullivanSullivan400 acres-
24Big Long LakeLaGrange392 acres82 ft
25Oliver LakeLaGrange390 acres89.9 ft
26Heritage LakePutnam356 acres-
27Lake PleasantSteuben355 acres51.8 ft
28Lake GageSteuben337 acres65.9 ft
29Lake WavelandParke337 acres19 ft
30Koontz LakeStarke324 acres-
31Grandview LakeBartholomew322 acres80.1 ft
32Adams LakeLaGrange302 acres90.9 ft
33Huntington LakeHuntington298 acres-
34Lake GeorgeLake276 acres-
35Lake KickapooSullivan258 acres40 ft
36Bruce LakeFulton247 acres27.9 ft
37Blue LakeWhitley246 acres45.9 ft
38Palestine LakeKosciusko245 acres26.9 ft
39Witmer LakeLaGrange238 acres54.1 ft
40Big LakeNoble236 acres69.9 ft
41Lake LouisePorter226 acres-
42Loon LakeWhitley226 acres91.9 ft
43Silver LakeSteuben214 acres-
44Crooked LakeWhitley205 acres-
45Waubee LakeKosciusko199 acres50.9 ft
46Christmas LakeSpencer198 acres26.9 ft
47Hoffman LakeKosciusko194 acres34.1 ft
48Lake HolidayLake192 acres-
49Bischoff ReservoirRipley192 acres-
50Papakeechie LakeKosciusko187 acres40 ft

Get updates on Indiana's largest lakes

New water-quality readings for Indiana lakes as IDEM publishes them. Unsubscribe anytime.

Frequently Asked Questions

What is the largest lake in Indiana?

Monroe Lake, at 10,750 acres, in Monroe County. Lake Michigan is a Great Lake shared with Michigan, Wisconsin and Illinois. IDEM states Indiana 'can only lay claim to about 1% (224 mi²) of Lake Michigan's area and 45 miles of its shoreline' (https://www.in.gov/idem/lakemichigan/about-lake-michigan/), so it is not treated as an Indiana lake. Source: Indiana Department of Natural Resources (Division of State Parks), 2026-07-30.

How is lake surface area measured?

Surface area comes from state DNR lake surveys and, for reservoirs, US Army Corps of Engineers (USACE) National Inventory of Dams records. Area is reported in acres at normal pool level. Reservoirs rise and fall with management and drought, so their listed area is the long-term normal rather than a single-day reading.

Are Indiana's largest lakes natural or reservoirs?

Of the top 50 Indiana lakes by area, 4 sit on a dammed river (reservoirs) and 46 are natural basins. Glacial states (MN, WI, MI, NY) skew natural; plains and southern states (MO, IA, ND, OH) skew toward reservoirs built for water supply, flood control, and recreation.

Do larger lakes have better water quality?

Not reliably. Quality varies more within a big lake than between lakes — a large lake can have a clean, deep main basin and a murky, algae-prone bay fed by a tributary, so one reading can mask wide swings. Depth, watershed land use, and how fast the lake flushes matter far more than raw surface area.

How big is the typical Indiana lake in this ranking?

Across the top 50 Indiana lakes by surface area, the median is 356 acres (Heritage Lake). This list is biased toward the biggest waters; the typical Indiana lake is far smaller.

Where to stay near Indiana's largest lakes

Planning a trip? Jump to live cabin, resort, and hotel availability near Indiana's biggest lakes.