Lakes / California / Merced County / O'Neill Forebay
O'Neill Forebay, California
2,246 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - California
37.08 degrees N, 121.05 degrees W - Merced 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 O'Neill Forebay Stacks Up
- Larger than 95% of the 1,147 lakes counted in California.
- About 74 miles from Fresno, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| San Luis Reservoir | Merced | 4.3 mi | 12,831 acres |
| San Luis Reservoir | Merced | 5.2 mi | 138 acres |
| San Luis Holding Reservoir | Merced | 8.6 mi | 66 acres |
| Los Banos Reservoir | Merced | 8.7 mi | 469 acres |
| Los Banos Creek | Merced | 11 mi | 46 acres |
| Los Banos Creek | Merced | 12 mi | 40 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About O'Neill Forebay
How Big Is O'Neill Forebay?
O'Neill Forebay covers 2,246 acres in Merced County, California.
What Is the Largest Lake in Merced County?
San Luis Reservoir is the largest lake in Merced County, at 12,831 acres.
Largest Lakes in California
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Salton Sea | Imperial | 233,096 acres | - |
| 2 | Lake Tahoe | Placer | 122,975 acres | - |
| 3 | Goose Lake | Modoc | 93,048 acres | - |
| 4 | Honey Lake | Lassen | 59,917 acres | - |
| 5 | Mono Lake | Mono | 45,124 acres | - |
All 1,147 California lakes ranked by surface area
Sources: USGS NHD (The National Map NHD MapServer layer 12) named waterbodies FTYPE 390/436; counties via Census point-in-polygon lake data (ID 102756893). Verified October 30, 2026.