The Green River is the Rio Verde of the Spaniards, who named it from its timbered shores and grassy islets: it is called by the Yuta Indians Piya Ogwe, or the Great Water; by the other tribes Sitskidiágí, or “Prairie-grouse River.” It was nearly at its lowest when we saw it; the breadth was not more than 330 feet. In the flood-time it widens to 800 feet, and the depth increases from three to six. During the inundation season a ferry is necessary, and when transit is certain the owner sometimes nets $500 a week, which is not unfrequently squandered in a day. The banks are in places thirty feet high, and the bottom may average three miles from side to side. It is a swift-flowing stream, running as if it had no time to lose, and truly it has a long way to go. Its length, volume, and direction entitle it to the honor of being called the head water of the great Rio Colorado, or Colored River, a larger and more important stream than even the Columbia. There is some grand exploration still to be done upon the line of the Upper Colorado, especially the divides which lie between it and its various influents, the Grand River and the Yaquisilla, of which the wild trapper brings home many a marvelous tale of beauty and grandeur. Captain T. A. Gove, of the 10th Regiment of Infantry, then stationed at Camp Floyd, told me that an expedition had often been projected: a party of twenty-five to thirty men, well armed and provided with inflatable boats, might pass without unwarrantable risk through the sparsely populated Indian country: a true report concerning regions of which there are so many false reports, all wearing more or less the garb of fable--beautiful valleys inclosed in inaccessible rocks, Indian cities and golden treasures--would be equally interesting and important. I can not recommend the undertaking to the European adventurer: the United States have long since organized and perfected what was proposed in England during the Crimean war, and which fell, as other projects then did, to the ground, namely, a corps of Topographical Engineers, a body of well-trained and scientific explorers, to whose hands the task may safely be committed.[114] [114] The principal explorers under the United States government of the regions lying west of the Mississippi, and who have published works upon the subject, are the following: 1. Messrs. Lewis and Clarke, in 1804-6, first explored the Rocky Mountains to the Columbia River. 2. Major Z. M. Pike, in 1805-7, visited the upper waters of the Mississippi and the western regions of Louisiana. 3. Major, afterward Colonel S. H. Long, of the United States Topographical Engineers, made two expeditions, one in 1819-20 to the Rocky Mountains, another in 1823 to the Sources of the St. Peter and the Lake of the Woods, whereby four volumes octavo were filled. 4. Governor Cass and Mr. Schoolcraft in 1820 explored the Sources of the Mississippi and the regions west and south of Lake Superior.