Extremely difficult terrain to start. A southbounder or “SOBO” begins with the hardest part of the Trail first. Unlike starting in other more moderate sections of the Trail, you do not have a chance to get your trail legs under you before hitting the steepest mountains. Katahdin, the mountain you climb on your first day, is arguably the hardest climb on the A.T. It features more than 4,000 feet of elevation gain, the greatest sustained ascent on the entire Appalachian Trail. It is a scramble. Expect to use your hands as you climb over steep boulders and ledges above treeline. As you head south into the Hundred Mile Wilderness, the mountains may seem small because of modest elevations, but they are some of the most rugged in Maine. Expect the footing to be on rocks, roots and mud rather than a smooth footpath.
Swarming insects. If you start in June, you will encounter insects. The most infamous are Maine’s black flies, which are out in swarms at the end of May and the beginning of June. They hatch in the cold clear streams and are an indication of healthy and clean water, but their sting hurts and their bites itch for days. Mosquito season lasts from May through the beginning of July, but there can be hatches later in the season depending on weather. Deer flies, gnats and horse flies make more local appearances through the early summer months. If you hike in Maine in early summer, a headnet is highly recommended.
Ticks carrying Lyme disease and anaplasmosis are being found in increasing numbers in Maine as well (though are present trailwide. Be sure to take educate yourself on tick-borne diseases and how to protect yourself here.