Cuillin Cuillin The Cuillin ( or ') is a range of rocky mountains located on the Isle of Skye in Scotland. The main Cuillin ridge is also known as the Black Cuillin to distinguish it from the Red Cuillin (', known locally as Red Hills), which lie to the east of Glen Sligachan. The peaks of the Black Cuillin are mainly composed of gabbro, a very rough igneous rock which provides a superb grip for mountaineers; and basalt, which can be very slippery when wet. The rocks forming the ridge of the Black Cuillin (and outliers such Bla Bheinn) are dark
Sweet Grass Hills feet), East Butte (with two peaks, the taller of which at 6,958 ft), and Mount Lebanon (5807 ft). The Sweet Grass Hills are an example of the island ranges that dot the central third portion of the state of Montana. These island ranges, completely surrounded by the 'sea' of plains and not geographically (or often geologically) part of the Rocky Mountains to the west, are "biological hotspots", containing more species than the prairie below. The hills were formed in the early Paleogene period, and geologically are known as stocks - intrusive igneous rock forced up from below and solidified. Because