Scottish Highlands in the Torridon Hills such as Liathach and Beinn Eighe in Wester Ross. These foundations are interspersed with many igneous intrusions of a more recent age, the remnants of which have formed mountain massifs such as the Cairngorms and the Cuillin of Skye. A significant exception to the above are the fossil-bearing beds of Old Red Sandstone found principally along the Moray Firth coast and partially down the Highland Boundary Fault. The Jurassic beds found in isolated locations on Skye and Applecross reflect the complex underlying geology. They are the original source of much North Sea oil. The Great Glen
Hills in the Puget Lowland contain several peaks over high, including the Fidalgo Island high point, Mount Erie. Mason County's Olympic Mountains foothills are called the Satsop Hills. Hills in the Puget Lowland Hills in the Puget Lowland, between the Cascades and the Olympic Mountains, including the entire Seattle metropolitan area, are generally between and rarely more than above sea level. Hills are often notable geologically and for social reasons, such as the seven hills of Seattle. The Puget Lowland lies between the Cascades and Olympic Mountains and once contained a plateau of glacial till not usually more than above sea level. The plateau, "the