| Sylvan Lake | |
|---|---|
| Rock formations near lake | |
| Location | Custer County, South Dakota, USA |
| Primary outflows | Sunday Gulch Creek |
| Basin countries | United States |
| Surface area | 17.3 acres (7.0 ha)[1] |
| Average depth | 12.8 feet (3.9 m)[1] |
| Max. depth | 30 feet (9.1 m)[1] |
| Shore length1 | 1 mile (1.6 km) |
| Surface elevation | 6,145 feet (1,873 m)[1] |
| 1 Shore length is not a well-defined measure. | |
Sylvan Lake, known as the "crown jewel" of Custer State Park, is located in the Black Hills of South Dakota. Created in 1881 when Theodore Reder built a dam across Sunday Gulch,[2] it offers picnic areas, rock climbing, small rental boats, swimming, and hiking trails. It is also popular as a starting point for excursions to Harney Peak and The Needles.
The lake was featured in the 2007 film National Treasure: Book of Secrets. The film made the lake appear to be located directly behind Mount Rushmore when in fact it is five miles southwest of the monument.