An organization that’s developing a backcountry network of huts along 180 miles of trails in Maine’s western mountains is opening the fourth of 12 lodges that are planned for the trails. Maine Huts and Trails says the Stratton Brook Hut is opening Dec. 21 in Carrabassett Valley, with views of both the valley and Sugarloaf Mountain. The hut will have 10 rooms and be able to sleep up to 44 people. The planned 180-mile hut-to-hut trail is open for hikers, mountain bikers, cross-country skiers and other outdoor enthusiasts. Each shelter has a main lodge, rooms with beds, hot showers and home-cooked meals. So far, Maine Huts has developed 50 miles of trails with three huts.