With the exception of the area around Blue Bell Resort  in the southwestern corner of the park, there is a lake or pond located near each of the major lodging areas in Custer State Park . Swimming is allowed at all locations but be aware that there are no lifeguards on hand. The park admission fee includes use of all of the beaches.
Fishing is permitted in all of the park waters with a valid South Dakota fishing license, which can be obtained at any of the resort areas in the park. Non-resident licenses are $14 per day, $32 for three days. (Residents pay a $7 per day fee or $25 annual license fee.) Fly-fishing lessons are available at the State Game Lodge  (605/255-4541, $200–375).
Boat rentals are provided at some of the lakes and may include paddleboats, kayaks, rowboats, or hydro-bikes. Hourly rates for rentals are per person and are $5 for a half-hour, $10 an hour. Half-day and full-day boat rentals are available for $100 and $150, respectively. Life jackets are included with the rental fees.
Sylvan Lake is located in the high-elevation area near Harney Peak  in the most northwestern spur of the park. From the town of Custer Head go east on Mount Rushmore Road and then turn left (north) onto Route 89 and follow the signs. From Hill City , head south about three miles on Route 385 and turn left on Route 87. From within the park, the lake is the end point of the Needles Highway , Route 87 headed north. It is a small lake but is the prettiest lake in the park with wonderful views of the surrounding granite formations. Large boulders line the lake. An easy, one-mile walking trail  meanders around the lake and trailheads for hikes to Harney Peak , the Little Devils Tower Trail, and the Sunday Gulch Trail  are found here.
There is a small beach area for swimming. There are ducks to watch and mountain goats are frequently visible on the high granite outcroppings nearby. Paddleboats, kayaks, and rowboats are available for rental here. The Sylvan Lake general store (May–Oct. daily 7 a.m.–9 p.m.) sells bait and fishing licenses, in addition to souvenirs, gifts, and fast food.
Brook and rainbow trout are the most likely catches here. Boats with small electric motors are allowed on the lake, but as small as the lake is, it seems more suited to rowboats.
Stockade Lake is the biggest lake in the park and is located on the far west boundary of the park. The town of Custer  is just down the road (Mt. Rushmore Rd./Rte. 16A). Stockade Lake offers the best fishing in the park. In addition to the rainbow, brown, and brook trout, found everywhere in the park, it is not uncommon for anglers to catch northern pike, bass, perch, crappie, and bullhead here. This is the only lake in the park that allows gas-powered engines on boats and there is a boat ramp available. This is still a very small lake, however, so don’t expect to go water-skiing. There are camping facilities near the lake and there is a small sandy beach for swimming.
Legion Lake is located along Route 16A in the northern third of the park. There is a restaurant and gift shop on-site that sells bait and other fishing supplies during the summer months, and cabins are available for rent. Paddleboats, kayaks, and hydro-bikes are available right next to the lodge. There is a swimming beach here that is tucked back from the lodge and away from view of the road, which makes it feel nice and secluded. Look to catch rainbow and brook trout. Boats with electric motors are allowed.
Center Lake is the most remote of the lakes in the park. A three-mile hike from the Grace Coolidge Campground parking lot, just past the park office on Route 16A, will bring you to the lake. Drive-in access to the lake is possible as well. From Route 16A in the park, take Route 87 north to the intersection with County Road 753 and follow signs for the Black Hills Playhouse . Go past the turnoff to the Playhouse and take your next right on Center Lake Road. This will bring you straight to the lake. There is a picnic area and swimming beach located on the north end of the lake. This is one of the quietest areas in the park. Rainbow, brown, and brook trout are the most common catches.