The Kittatinnies are part of the Ridge and Valley province of the Appalachian Mountains. In Pennsylvania, the ridge forming the Kittatinnies becomes known as Blue Mountain and runs southwest for 150 miles, nearly to Maryland. In Franklin County, PA, however, a parallel ridge to Blue Mountain is named "Kittatinny Mountain"; the Pennsylvania Turnpike tunnels through both ridges, with the western tunnel named "Kittatinny Mountain" and the eastern one, "Blue Mountain." To the north in New York, the ridge is known as the Shawangunk Mountains. These mountains mark the northern and western edge of the Great Appalachian Valley.