Short Hike &x28;8&x29; - Large Poison Ivy Vine (Toxicodendron Radicans) On An Oak Tree Along The Katellen Trail, Northampton County. The One-mile, Blue-blazed Katellen Trail (named For The Village Of Katellen, Where The Trail Begins) Ascends The South Slope Of Blue Mountain Before Joining The White-blazed Appalachian Trail At The Summit. I've Licensed This Photo As CC0 For Release Into The Public Domain. You're Welcome To Download The Photo And Use It Without Attribution. Photo