When Jim Mitchell heard two years ago that a group of paddlers was trying to establish a network of campsites along the Penobscot River, he looked at his backyard — a formerly tangled mess of bushes and overgrowth on the southwest side of French Island in Old Town — and decided he’d like to play a role in the plan. Today, Mitchell’s one-acre backyard parcel has become a gem of the Penobscot River Paddling Trail, featuring seven tent sites and a spectacular view of the river. “It shares some commonality [with other sites] in that there’s camping by the river, but other than that it’s a little different,” Mitchell said as he gave a tour of the grounds. “This was land that wasn’t open, and for five years I’d been clearing it by hand,” Mitchell said.