Lakes / California / San Mateo County / Upper Crystal Springs Reservoir
Upper Crystal Springs Reservoir, California
595 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - California
37.50 degrees N, 122.34 degrees W - San Mateo 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 Upper Crystal Springs Reservoir Stacks Up
- Larger than 84% of the 1,147 lakes counted in California.
- The largest lake in San Mateo County among those counted.
- About 20 miles from San Francisco, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Lower Crystal Springs Reservoir | San Mateo | 2.9 mi | 586 acres |
| Central Lake | San Mateo | 5.6 mi | 239 acres |
| Pilarcitos Lake | San Mateo | 6.4 mi | 89 acres |
| San Andreas Lake | San Mateo | 8.5 mi | 486 acres |
| Lake Merced | San Francisco | 18 mi | 208 acres |
| Lake Merced | San Francisco | 18 mi | 92 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Upper Crystal Springs Reservoir
How Big Is Upper Crystal Springs Reservoir?
Upper Crystal Springs Reservoir covers 595 acres in San Mateo County, California.
What Is the Largest Lake in San Mateo County?
Upper Crystal Springs Reservoir is the largest lake in San Mateo County, at 595 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 120030676). Verified October 30, 2026.