The bulk of the North Cascades consists of deformed and metamorphosed, structurally complex pre-Tertiary rocks. These originated in diverse locations around the globe: the area is built of several (perhaps ten or more) different terranes of different ages and origins. These terranes are separated by a series of ancient faults, the most significant being the Straight Creek Fault, which runs north-south from north of Yale, British Columbia, through Hope, Marblemount, Washington, and down to Kachess Lake near Snoqualmie Pass. There is evidence of significant strike-slip movement on this fault in the past, with similar rocks on either side of the fault separated by dozens of miles. This is thought to be related to northward tectonic movement of the West Coast relative to the rest of North America.