Captain Clark continued his observations up the long series of rapids and falls until he came to a group of three small islands to which he gave the name of White Bear Islands, from his having seen numerous white, or grizzly, bears on them. On the nineteenth of June, Captain Clark, after a careful survey of the country on both sides of the stream, decided that the best place for a portage was on the south, or lower, side of the river, the length of the portage being estimated to be about eighteen miles, over which the canoes and supplies must be carried. Next day he proceeded to mark out the exact route of the portage, or carry, by driving stakes along its lines and angles. From the survey and drawing which he made, the party now had a clear and accurate view of the falls, cascades, and rapids of the Missouri; and, it may be added, this draught, which is reproduced on another page of this book, is still so correct in all its measurements that when a Montana manufacturing company undertook to build a dam at Black Eagle Falls, nearly one hundred years afterwards, they discovered that their surveys and those of Captain Clark were precisely alike. The total fall of the river, from the White Bear Islands, as Lewis and Clark called them, to the foot of the Great Falls, is four hundred twelve and five-tenths feet; the sheer drop of the Great Fall is seventy-five and five-tenths feet. The wild, trackless prairie of Lewis and Clark’s time is now the site of the thriving town of Great Falls, which has a population of ten thousand. Here is a lucid and connected account of the falls and rapids, discovered and described by Lewis and Clark: