South Twin Lake Campground is the only campground directly on busy South Twin Lake, located across the road from West South Twin Campground and sharing a driveway and a small boat ramp with Twin Lakes Resort. While it is roughly the same size as the nearby West South Twin, North Twin Lake, and Sheep Bridge campgrounds, South Twin Lake Campground is easily the most crowded, being full all summer long. Reservations must made well in advance for the 10 sites that allow them, and the 11 walk-in sites are seldom vacant.

South Twin Lake’s proximity to the resort is the reason why the campground is so crowded. The resort offers a plethora of amenities such as showers, a general store, and even a restaurant. Between the campground and the resort is a small boat launch; however, just like North Twin Lake, powerboats are prohibited. As a result, paddlers are abundant on South Twin Lake. The resort has paddleboat, paddleboard, and kayak rentals by the hour that many people who camp at South Twin Lake opt to use.

South Twin Lake campground is usually open from late April to the first weekend in October. The day use area stays open for a bit longer though, because the resort will stay open later into October until it is inaccessible due to snow.