Construction work has started on key parts of Don Carter State Park off northeastern Lake Lanier, with the opening now expected in summer 2013. During a visit Monday afternoon, dump trucks and bulldozers were rolling along dirt-packed and gravel roads fingering throughout the 1,040-acre park. When completed, Hall County’s first state park will feature 48 camp sites with water and electricity, eight two-bedroom cottages, visitors center, playgrounds, two boat ramps and a beach/bathhouse in a scenic cove off the Chattahoochee River.