Appalachian Trail - Winter-SOBO6-This Is Tough This Is Maine - Caratunk to Kingfield Apalachian Trail Thru Hike Slang Meanings NOBO - Thru Hike-Starting at Georgia going North to Maine-AT 2192 Miles SOBO - Thru Hike-Starting at Maine going South to Georgia-AT 2192 Miles YOYO - Thru Hike-Starting at Georgia going North to Maine-AT 2192 Miles then, turn around -Starting at Maine going South to Georgia-AT 4,384 Miles in 365 days. Flipflops - Thru Hike-Starting at Harpers Ferry, [~Middle of AT] go North to Maine-Then from Harpers Ferry going South to Georgia-AT 2192 Miles Springer Mountain, Georgia -- Southern Terminus Mount Katahdin, Maine -- Northern Terminus Triple Crown - Person who has Thru Hiked the big 3 Trails, AT, CDT, PCT Appalachian Trail__ Continental Divide Trail__ Pacific Crest Trail Calendar Year Triple Crown _ Hike all 3 trails in 365 days.