Lakes / Indiana / Marion County / Geist Reservoir
Geist Reservoir, Indiana
1,863.74 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Indiana
39.92 degrees N, 85.96 degrees W - Marion County. State and county outlines drawn from Census boundary data; the lake marker is placed by its USGS National Hydrography Dataset coordinates, not by eye. Schematic - not a survey map.
How Geist Reservoir Stacks Up
- Ranks #10 for surface area among the Indiana lakes counted so far - 1,863.74 acres.
- The largest lake in Marion County among those counted.
- About 15 miles from Indianapolis, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Indian Lake | Marion | 3.0 mi | 60.77 acres |
| Lake Woodland | Hamilton | 7.8 mi | 47.83 acres |
| Sugar Hills Lake Dam | Hancock | 8.4 mi | 78.21 acres |
| Morse Reservoir | Hamilton | 13 mi | 1,440.16 acres |
| Eagle Creek Reservoir | Marion | 19 mi | 1,268.23 acres |
| Wurster Lake | Boone | 20 mi | 33.08 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Geist Reservoir
How Big Is Geist Reservoir?
Geist Reservoir covers 1,863.74 acres in Marion County, Indiana.
What Is the Largest Lake in Marion County?
Geist Reservoir is the largest lake in Marion County, at 1,863.74 acres.
Largest Lakes in Indiana
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Monroe Lake | Monroe | 11,112.45 acres | - |
| 2 | Patoka Lake | Orange | 9,120.83 acres | - |
| 3 | Brookville Lake | Franklin | 4,364.22 acres | - |
| 4 | Lake Wawasee | Kosciusko | 3,426.28 acres | - |
| 5 | Broad Pond | Gibson | 2,941.52 acres | - |
All 425 Indiana lakes ranked by surface area
Sources: USGS National Hydrography Dataset (The National Map) lake data (ID {e42a08d4-6248-4b46-8333-9d887dd3433d}). Verified October 30, 2026.