Lakes / Wyoming / Platte County / Grayrocks Reservoir
Grayrocks Reservoir, Wyoming
3,600.33 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Wyoming
42.15 degrees N, 104.74 degrees W - Platte County. State and county outlines drawn from Census boundary data; the lake marker is placed by its Wyoming Game and Fish Department coordinates, not by eye. Schematic - not a survey map.
How Grayrocks Reservoir Stacks Up
- Larger than 97% of the 783 lakes counted in Wyoming.
- About 70 miles from Cheyenne, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Guernsey Fish Pond | Platte | 7.7 mi | 8 acres |
| Guernsey Reservoir | Platte | 12 mi | 2,377 acres |
| Detention Reservoir Case Bier 1 | Goshen | 13 mi | 29.77 acres |
| Reservoir Number Three | Platte | 13 mi | 164.5 acres |
| Festo Lake | Platte | 14 mi | 42.26 acres |
| Reservoir Number One | Platte | 17 mi | 99.83 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Grayrocks Reservoir
How Big Is Grayrocks Reservoir?
Grayrocks Reservoir covers 3,600.33 acres in Platte County, Wyoming.
What Is the Largest Lake in Platte County?
Glendo Reservoir is the largest lake in Platte County, at 12,365 acres.
Deepest Natural Lakes in Wyoming
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Deep Lake | Park | 285 acres | 472 ft |
| 2 | Lake Reno | Park | 107 acres | 222 ft |
| 3 | Snowdrift Lake | Teton | 57 acres | 174 ft |
| 4 | Crater Lake | Big Horn | 39 acres | 166 ft |
| 5 | Beauty Lake | Park | 94 acres | 165 ft |
All 120 Wyoming lakes ranked by depth
Largest Lakes in Wyoming
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Yellowstone Lake | Teton | 84,442 acres | - |
| 2 | Flaming Gorge Reservoir | Sweetwater | 38,888.36 acres | 440 ft |
| 3 | Jackson Lake | Teton | 26,853.22 acres | - |
| 4 | Pathfinder Reservoir | Carbon | 22,000 acres | 192 ft |
| 5 | Seminoe Reservoir | Carbon | 20,000 acres | 200 ft |
All 783 Wyoming lakes ranked by surface area
Sources: USGS National Hydrography Dataset (The National Map) lake data (ID 136893587). Verified October 30, 2026.