Show ISLANDS IN ASEA OF LAVA the vall valley ey of the ancient snake river in idaho was flooded with great outpourings of black lava which spread out sheet on sheet buried the old land surface and partly filled the valley with molten rock which solidified and has remained to this day undisturbed except for the gorges that the sti earns have cut in it in some places old mountains project through the petrified lava flood as isla islands n ds project above the surface odthe of the sea and old ridges stick out into was capes and promontories the thear abeal ea covered by the snake river lava is about square miles so far as is riba known there is butone but one lava field in north america Ar of greater extent the Colu columbia hiba river lava field which aich covers about square miles in snake river can canyon y on below shoshone falls F alls nearly feet of horizontal sheets of lava lav aare are exposed but whether this is the maximum thickness or not cn can not behold be told |