Largest Lakes in Indiana
5 Indiana lakes with measured surface area, ranked by acreage. The biggest lake in Indiana is Lake Lemon, which tops the list at 1,650 acres in Monroe County.
Reading Indiana's size profile
Indiana's largest lake by surface area is Lake Lemon in Monroe County, spanning 1,650 acres. Most of Indiana's biggest waters are reservoirs — dammed river valleys built for water supply, flood control, and recreation, so their footprints shift with pool level.
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 report card with grade, clarity, depth, and EPA impairment status. Area figures come from state DNR surveys and the USACE National Inventory of Dams; grades come from EPA and state monitoring data.
The 5 biggest lakes in Indiana by surface area
| # | Lake | County | Surface area | Max depth | Grade |
|---|---|---|---|---|---|
| 1 | Lake Lemon | Monroe | 1,650 acres | - | F |
| 2 | Webster Lake | Kosciusko | 774 acres | - | D |
| 3 | Lake George | Steuben | 538 acres | - | B |
| 4 | Koontz Lake | Starke | 324 acres | - | D |
| 5 | Lamb Lake | Johnson | 56 acres | - | C |
Frequently Asked Questions
What is the largest lake in Indiana?
The largest lake in Indiana in the LakeGrade dataset is Lake Lemon in Monroe County at 1,650 acres. Water quality grade: F.
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 5 Indiana lakes by area, 5 sit on a dammed river (reservoirs) and 0 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 grade 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 5 Indiana lakes by surface area, the median is 538 acres (Lake George). 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.
- Lake Lemon · Monroe CountyCabins & hotels near Lake Lemon →
- Webster Lake · Kosciusko CountyCabins & hotels near Webster Lake →
- Lake George · Steuben CountyCabins & hotels near Lake George →
- Koontz Lake · Starke CountyCabins & hotels near Koontz Lake →
- Lamb Lake · Johnson CountyCabins & hotels near Lamb Lake →