REPORT OF F. V. HAYDEN ON THE GEOGRAPHY OF THE 

 MISSOURI VALLEY. 



Sir : In accordance with instructions, I have the honor to submit the 

 accompanying preliminary report of geological surveys during the sea- 

 son of 1868, preceding it with a brief outline of the physical geography 

 of the Missouri Valley. 



^Nearly all the vast area west of the Mississippi may be divided into 

 mountain and prairie, for very soon after passing westward from Leav- 

 enworth there is very little timber to be seen except that which skirts 

 the streams. This consists mostly of cotton-wood ; a few low oaks or 

 pines are found on the dry hills, and here and there an elm or ash. The 

 whole surface is undulating ', ridge on ridge and hill on hill as far as the 

 eye can reach. This combination of mountain and prairie may be said 

 to comprise what is generally known as the Eocky Mountain region. 

 As we proceed westward, we find that the ascent is gradual, at first not 

 more than one foot per mile, gradually increasing until we approach the 

 mountain-elevations, when the grade of ascent becomes 40 to 50 feet per 

 mile. If we examine in their order some of the barometrical profiles 

 which have been made along the lines of the routes explored for the 

 Pacific Eailroad, we can readily ascertain the gradual ascent, toward the 

 mountain-elevations. 



Leaving Saint Louis westward, we gradually ascend, passing over a 

 prairie country for the most part, for the distance of nearly 800 miles, 

 and when we have reached an elevation of 6,000 feet above the sea we 

 come abruptly to the lofty rugged peaks which compose the various 

 series of elevated ridges. Examining the map of the country west of the 

 Mississippi, published by the War Department, we observe that the 

 immediate Rocky Mountain region is not composed of merely a single 

 lofty upheaved ridge exteudiug across the continent, but a vast series of 

 ridges or ranges which, taken singly, do not seem to have any definite 

 trend, but, when viewed in the aggregate, extend across the map in a 

 direction nearly northwest and southeast, forming a zone or belt 500 to 

 1,000 miles in width from east to west. 



From longitude 96"^ westward to the foot of the mountain-ridges, the 

 country traversed exhibits the true typical prairie, no timber being found 

 to any extent, except that which skirts the streams. From thence to 

 the Pacific coast we have what may be called the true mountain portion, 

 which is composed of a vast number of ridges of elevation, interspersed 

 with beautiful valleys, many of which are remarkable for their fertility. 

 Some of the valleys are quite large and surrounded by the mountain- 

 ridges as by gigantic walls. 



If we examine the barometrical profile constructed by Governor Ste- 

 vens, from Saint Paul, Minnesota, to the foot of the mountains westward, 

 we find that the former locality is 828 feet above the sea-level. ISTear 

 the mouth of the Yellowstone, 670 miles to the westward, we find that the 

 elevation is 2,010 feet above the sea, and that we have made a gradual, 

 almost imperceptible ascent of, in that distance, 1,172 feet, or an average 

 of nearly two feet to the mile. As we approach the base of the mount- 



