The Clare Valley is a small wine valley about 136 km north of Adelaide, with an old railway line turned bike trail running down its middle and the copper town of Burra just to the north. It suits a slow weekend: a ride between the vineyards, a picnic, and an afternoon exploring a mining town that is almost a museum in itself.
Because the valley is small, every campground is a short drive from the Riesling Trail. Discovery Parks Clare is at the northern end, and at the southern end, Riverton and Saddleworth are on the Gilbert River, with powered sites and a dump point at Saddleworth. North of the valley, Burra Caravan & Camping Park is a short walk from the old town's museums.
The Riesling Trail follows the old railway for 25 km past the vineyards to Auburn, and its gentle grade makes it a good ride for kids on bikes. Burra, a State Heritage Town since 1994, is the big day out: the mine site with its open-cut pit and engine house, the miners' dugouts cut into the creek bank, and Redruth Gaol, used to film Breaker Morant. Back in Clare, the Old Police Station Museum is in town, and Bungaree Station, 12 km north, has one of Australia's oldest working woolsheds, built from 1842.
From Auburn, the Riesling Trail joins the Rattler Trail, so a long day's ride can run all the way down the valley to Riverton. Near Clare, Spring Gully Conservation Park protects a rare red stringybark woodland, and around the valley and Burra there are lookouts such as Neagles Rock and the Burra Copper Mine Lookout over the old pit.
Yes. One campground here has powered sites confirmed: Saddleworth Caravan Park. For the rest we are still confirming, so check with the park or holiday park before you book a powered site.
Clare is about 136 km north of Adelaide and Burra about 156 km. At the southern end of the valley, Riverton is about 94 km and Saddleworth about 103 km from Adelaide.
Facts from Wikipedia, "Clare, South Australia" (CC BY-SA 4.0), Wikipedia, "Burra, South Australia" (CC BY-SA 4.0), Wikipedia, "Riverton, South Australia" (CC BY-SA 4.0) and Wikipedia, "Saddleworth, South Australia" (CC BY-SA 4.0).

Region boundary: ABS ASGS Edition 3 Tourism Regions 2021 (Tourism Research Australia), CC BY 4.0.