Lake water shows through the trees behind a rig backed onto a wooded Allatoona site, and the swimming beach and the dock are a short walk down the loop. Allatoona's shoreline runs 270 miles through the hills just north of Marietta and out along the Etowah arm, and the lake ranks among the most visited Corps of Engineers lakes in the country. In a motorhome you hold one site for the whole week, wake to the same cove every morning and keep the air running through the July afternoons while the day crowd loads its boats and heads home.
The week mostly happens within sight of the rig: morning swims off the campground beach, a boat at the dock if you brought one, dinner outside while the cove goes dark. Which beach depends on which of the three Corps campgrounds you book.
Payne, off Highway 92 near Acworth, is the closest of the three to Marietta and the smallest, with 57 reservable sites near its dock and swimming beach and electric at the standard sites. McKinney, also on the Acworth side, is the big wooded loop, where each of the 150 sites has 50-amp electric and its own water, with a shower house and a dump station on the grounds.
Sweetwater, up Highway 20 toward Canton, is the one for a site right on the water, with lakefront sites near the beach and dock and electric at the standard sites, a dump station and a fresh-water fill. None of the three lists sewer at the site, so a week runs on the tanks with a stop at the McKinney or Sweetwater dump on the way out.
Summer is when Allatoona is busiest and when electric at the pad matters most, so lock the site before the rig. Every campsite on the lake is by reservation, and the lakefront loops are the ones to grab early for a July week. Neither the Corps nor Recreation.gov posts a length cap for McKinney, Sweetwater or Payne as of October 2026. Confirm the length of the site you land with the campground, then pick the rig that fits it.
Back in town, Atlanta-Marietta RV Park on Wylie Road has full hookups with sewer and up to 50-amp service, and a camping season that runs the whole year as of October 2026. It's the easy first night after a late start, with the lake waiting the next morning.
Days off the water stay close. Kennesaw Mountain rises over Marietta with no overnight of its own, Red Top Mountain State Park holds another shore of the same lake, and a Braves game at Truist Park fills an evening. The Marietta campervan page covers all three, and it's the smaller rig to look at if your site turns out tight or the trip is down to two people.
Carters Lake and Doll Mountain in the Blue Ridge foothills
North of Allatoona, the road into Doll Mountain switchbacks down a heavily wooded peninsula until the trees open onto Carters Lake. The lake spreads across 3,200 acres under the first Blue Ridge foothills, with 62 miles of shoreline and nothing built along it, so the view from the site is water and wooded hills. It's the cooler, quieter trip, best on a spring or fall weekend, and the steep approach is worth taking slowly in a long rig.
Doll Mountain is on the south shore off Highway 382, reached by way of I-75 and Highway 411, and 39 of its 65 sites have electric and water hookups, with a dump station on site. Woodring Branch, on the north shore off Highway 282, has electric and water at 31 of its 42 sites and its own dump station. Lake Lanier, the other big Corps lake north of the metro, is covered on the Atlanta RV page.