Lakes / Massachusetts / Berkshire County / Mount Williams Reservoir
Mount Williams Reservoir, Massachusetts
49.17 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Massachusetts
42.69 degrees N, 73.15 degrees W - Berkshire County. State and county outlines drawn from Census boundary data; the lake marker is placed by its Massachusetts Division of Fisheries and Wildlife coordinates, not by eye. Schematic - not a survey map.
How Mount Williams Reservoir Stacks Up
- Larger than 41% of the 784 lakes counted in Massachusetts.
- About 50 miles from Springfield, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Mauserts Pond | Berkshire | 5.2 mi | 49 acres |
| South Pond | Berkshire | 6.0 mi | 25 acres |
| Bog Pond | Berkshire | 6.7 mi | 40.28 acres |
| Lower Reservoir Bear Swamp | Berkshire | 9.5 mi | 107.34 acres |
| Cheshire Reservoir | Berkshire | 9.6 mi | 575 acres |
| Upper Reservoir Bear Swamp | Berkshire | 9.9 mi | 108.23 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Mount Williams Reservoir
How Big Is Mount Williams Reservoir?
Mount Williams Reservoir covers 49.17 acres in Berkshire County, Massachusetts.
What Is the Largest Lake in Berkshire County?
Onota Lake is the largest lake in Berkshire County, at 653 acres.
Deepest Natural Lakes in Massachusetts
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Walden Pond | Middlesex | 62 acres | 100 ft |
| 2 | Cliff Pond | Barnstable | 206 acres | 96 ft |
| 3 | Wallum Lake | Worcester | 322 acres | 81 ft |
| 4 | Onota Lake | Berkshire | 653 acres | 72 ft |
| 5 | Ashumet Pond | Barnstable | 220 acres | 69 ft |
All 211 Massachusetts lakes ranked by depth
Largest Lakes in Massachusetts
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Quabbin Reservoir | Franklin | 24,012 acres | - |
| 2 | Wachusett Reservoir | Worcester | 4,041 acres | - |
| 3 | Assawompset Pond | Plymouth | 2,652.37 acres | - |
| 4 | Watuppa Pond | Bristol | 1,758.37 acres | - |
| 5 | South Watuppa Pond | Bristol | 1,460 acres | 23 ft |
All 784 Massachusetts lakes ranked by surface area
Sources: USGS National Hydrography Dataset (The National Map) lake data (ID 50524493). Verified October 30, 2026.