The Blue Mountain or Blue Ridge region, like the ridgelines to its north and west, is one of a series of near parallel ridges that run for tens of miles, and are equally likely to be called Ridge or Mountain. Hence Blue Mountain is not to be confused with the Blue Ridge Mountains but instead, represents the sharp escarpment, a step in elevation separating the Appalachian Mountains from the pastoral basin famous as the landscape associated with the Pennsylvania Dutch in southern Pennsylvania called the Great Valley (A 'Physiographic Province', as are these section titles). Many of Pennsylvania's water gaps cut through Blue Mountain including Delaware Water Gap, Lehigh Gap, Schuylkill Gap, and Susquehanna Gap. Also along the ridge, many wind gaps also exist. (see separate article) The rocks of the Blue Mountain section include mostly Silurian aged sandstone, conglomerate, siltstone, shale, and some limestone. Blue mountain is also known by the names Kittatinny Mountain (especially in New Jersey) and Hawk Mountain. One of the most prominent rock types of this section is the Shawangunk Formation which is named after the Shawangunk Ridge of New York.