Cuillin in colour, particularly in the shade, but when in sunlight the Black Cuillin can appear grey to brown in colour. The main ridge forms a narrow crest, with steep cliffs and scree slopes. The ridge is about 14 km long (measured from Gars-behinn in the south to Sgùrr nan Gillean in the northeast), and curves in an irregular semi-circle around Loch Coruisk, which lies at the heart of the range. The highest point of the Cuillin, and of the Isle of Skye, is Sgùrr Alasdair in the Black Cuillin at 992 m (3,255 ft). The Red Cuillin are mainly composed
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