Sylvan Lake Fishing, Size, Depth, And More

Sylvan Lake
Jess Kraft/

Written by Colby Maxwell

Updated: July 15, 2023

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There are “Sylvan Lakes” all across the U.S., including lakes in New York, Colorado, and Florida. Perhaps the most notable is Sylvan Lake in Custer State Park, South Dakota. Sylvan Lake is located within the Black Hills of South Dakota, about five miles southwest of Mount Rushmore. It was created when Theodore Reder built the Sylvan Lake Water Dam across the Sunday Gulch Creek in 1891.

Today, Sylvan Lake has become a popular destination for swimmers and hikers. The lake even appears in the movie National Treasure: Book of Secrets. Let’s take a deeper look at this lake. It’s time to take discover all it has to offer and why it exists.


Sylvan Lake is a relatively small lake located in Custer State Park in the Black Hills of South Dakota. It’s within the boundary of Custer County, South Dakota, and is near the southwestern corner of the rectangularly-shaped state. Custer State Park is a popular park known for its granite peaks and plains, as well as beautiful mountain waters. Overall, Custer State Park is 71,000 acres and encompasses Sylvan Lake totally.

Notable nearby features of Sylvan Lake include the national memorial Mount Rushmore, about five miles to the southwest. Additionally, the Crazy Horse sculpture, Badlands National Park, Mammoth Site, Needles, and more are all found within the same region of the state.


Sylvan Lake

Sylvan Lake is a manmade lake with a short but fun history.

Sylvan Lake is a relatively new lake due to it being man-made. It formed in 1891 when a man named Theodore Reder built the Sylvan Lake Water Dam across the Sunday Gulch Creek. Once the dam blocked up the creek and the lake formed, the region gained some popularity, specifically in the form of a place known as the Sylvan Lake Lodge. Reder and his wife ran the lodge, then eventually sold it to J.C. Spencer and updated it sometime after 1896. The changes turned the lodge into a rather popular location and featured a gazebo and water activities during certain portions of the year.

A campground was later built across the lake, along with an icehouse to give the hotel ice during the summers. After going through new ownership again, the state of South Dakota eventually bought the lodge. After decades of success, a fire broke out, and the building was mostly destroyed, although the region’s popularity remained. The lodge would be rebuilt and reopened in 1938.

Aside from the popular lodge, the lake has another claim to fame via Hollywood. In the movie, National Treasure: Book of Secrets, the lake seen during scenes around Mount Rushmore is, in fact, Sylvan Lake. However, it was digitally changed to appear as if Mount Rushmore is visible in the background, although that isn’t the case in real life.

Today, Sylvan Lake remains a popular destination for water activities, nearby hiking, and a lot more.


Lake Sylvan has a surface area of 17.3 acres or 7.0 hectares. As far as lakes go, Sylvan Lake is on the smaller size, with the minimum size for a body of water to be called a lake usually between 5-20 acres measured via surface area. As far as the state records, Sylvan Lake doesn’t even crack the top 10 and isn’t large enough to even have significant development around it.

The shoreline is measured to be around 1 mile.


The average depth of Sylvan Lake is 12.8 feet, and the maximum depth is around 30 feet. In a higher elevation region of the U.S., the lake has a surface elevation of 6,145 feet.

Water Level

Since Sylvan Lake is so small and not depended upon as a reservoir for the nearby populations, water levels aren’t regularly taken or monitored. That being said, there are likely fluctuations in accordance with the seasons. During the winter, the lake forms ice. It once featured an icehouse that provided ice to the nearby hotel during the summer. When the lake is iced over, the water levels can be difficult to measure.


Fishing - Holding a Brown Trout

Brown and rainbow trout are the two main game fish that can be caught in Sylvan Lake.

Sylvan Lake is a popular destination for anglers who enjoy fishing for trout in a scenic setting. The lake covers 17 acres and has a maximum depth of 30 feet, giving it enough variability for a few species of fish.

It is home to several species of fish, but the most notable species for anglers are the brown and rainbow trout. These fish can be caught using various lures and live bait, such as grasshoppers, salmon eggs, and night crawlers. Anglers can fish from the shore or use their own non-motorized boats, canoes, or kayaks. They can also rent boats from the nearby campground.


Mount Rushmore National Memorial

Mount Rushmore National Memorial is quite close to Sylvan Lake, about five miles away.

Sylvan Lake is located in the Black Hills, a region of southwestern South Dakota that has a complex and diverse geologic history. The Black Hills were uplifted in the early Cenozoic era, about 65 million years ago, as a result of the Laramide orogeny that formed the Rocky Mountains.

The uplift exposed ancient rocks that date back to the Archean and Proterozoic eons, more than 2.5 billion years ago. These rocks include the Little Elk and Bear Mountain granites, the Harney Peak granite, and the Sioux quartzite. The Black Hills feature sedimentary rocks deposited during the Paleozoic and Mesozoic eras, such as the Deadwood Formation, the Dakota Sandstone, and the Pierre Shale. These rocks contain fossils of marine and terrestrial organisms, such as trilobites, ammonites, and dinosaurs. Scientists and researchers worldwide come to study the unique region and the fossils within the layers.

The Black Hills’ geology is influenced by volcanic activity, erosion, glaciation, and weathering. these events shaped the landscape and created features such as caves, canyons, and lakes, many of which are explored in-depth today.

Boating and Other Activities

Sylvan Lake is not only a great place for fishing but also for boating and other recreational activities. The lake allows non-motorized boats, such as canoes, kayaks, rowboats, and paddle boats. You can rent these from the Sylvan Lake General Store and Campground. The facility also offers camping sites, cabins, showers, and a convenience store.

There are activities to do at or near the lake, such as hiking, biking, swimming, picnicking, wildlife viewing, and rock climbing. In fact, there are a few hiking trails nearby. Trails at Sylvan Lake include Black Elk Peak Trailhead, the Cathedral Spires Trailhead, and the Sunday Gulch Trailhead. The lake is also close to other Black Hills attractions, such as Mount Rushmore, Crazy Horse Memorial, Custer State Park, and Wind Cave National Park.

Parking is accessible and only a short walk from the lake at the Sylvan Lake Pullout and Picnic Area. The Sylvan Lake Auditorium, the Sylvan Lake Fishing Pier, the Sylvan Lake Lodge, and the Cathedral Spires Cabin are also nearby.


Black Color, Elk, Mountain Peak, Mountain, South Dakota

The Black Hills of South Dakota offer a lot of outdoor fun and activities for people staying near Sylvan Lake.

Sylvan Lake offers camping via the Sylvan Lake Campground. It’s a great option to stay overnight and enjoy the lake, as well as the surrounding area. The campground has 39 RV and tent sites, each with a picnic table and a fire pit. The sites have electric hookups but no water or sewer. There are several water fill stations and a dump station available in the campground. The campground also has a modern shower house, a playground, and a camp store. The campground is open from May to September and operates on a first-come, first-served basis. Campers can make reservations online or by phone. Camping fees range from $25 to $30 per night, depending on the season. The campground is close to the lake, where you can rent boats, swim, fish, or hike.

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About the Author

Colby is a writer at A-Z Animals primarily covering outdoors, unique animal stories, and science news. Colby has been writing about science news and animals for five years and holds a bachelor's degree from SEU. A resident of NYC, you can find him camping, exploring, and telling everyone about what birds he saw at his local birdfeeder.

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