ROUTE NEAR THE THIRTY-EIGHTH AND THIRTY-NINTH PARALLELS. 17 



ROUTE NEAR THE THIRTY-EIGHTH AND THIRTY-NINTH PARALLELS OF NORTH LATITUDE. 



The general consideration that determined the position of the route to be examined near 

 the 38th and 39th parallels of latitude, was its central position geographically, it being about 

 midway between the northern and southern boundary lines of the United States, which is like 

 wise the position, nearly, of the Bay of San Francisco ; the two termini of the route, St. Louis 

 and San Francisco, being respectively in latitudes 39 and 38, nearly. Moreover, a route 

 near these parallels would probably give the shortest road from the Bay of San Francisco 

 to the navigable waters of the Mississippi. 



The exploration of the route conducted by Captain J. W. Gunnison, corps of Topographical 

 Engineers, commenced on the Missouri at the mouth of the Kansas, about 245 miles from the 

 Mississippi at St. Louis. The Kansas, and its branch called the Smoky Hill fork, were followed 

 to a convenient point for crossing to the Arkansas, the valley of this latter river having been 

 entered west of the Great Bend and near the meridian of 99. The route then ascended the 

 valley of the Arkansas to the mouth of Apishpa creek, fifty miles above Bent s Fort ; leaving 

 it here, and crossing to the entrance of the Rocky mountains, here called the Sierra Blanca, 

 at the Huerfano Butte, on the river of that name, a tributary of the Arkansas. The elevation 

 at this point is 6,099 feet ; its distance from Westport, mouth of the Kansas river, by the rail 

 road route, 654 miles. 



Of the several passes through the Rocky mountains connecting the tributaries of the Huerfano 

 with those of the Rio del Norte, but one, the Sangre de Cristo, was found practicable for a 

 railroad, the new and only practicable approach to this pass being explored by Capt. Gunnison. 

 By side location the summit, 9,219 feet above the sea, 692 miles from Westport, was attained, 

 and the descent made to the valley of the Rio Grande with practicable though heavy grades ; 

 and thence the grades were favorable to the vicinity of Fort Massachusetts. 



The western chain of the Rocky mountains is now to be crossed in order to gain and traverse 

 the basins of the two great tributaries of the Colorado of the West, Grand and Green rivers. 

 For this purpose the valley of San Luis, an extensive, uncultivable plain, covered for the most 

 part with wild sage, was ascended with easy grades to Sah watch creek, one of whose affluents 

 rises in a pass of the Rocky mountains, here called the Sahwatch mountains, known by the 

 name of the Coo-che-to-pa Pass. 



The approach to the summit of the pass, 10,032 feet above the sea, 816 miles from Westport, 

 is not favorable, the pass in this part having a defile character, overhung occasionally by 

 walls of igneous rock. To cross the summit, a grade of 124 feet per mile for several miles, 

 and a tunnel nearly two miles long, are required. The descent, with grades varying from 41 to 

 108 feet per mile, is by the valley of Pass creek, along which much cutting and filling will be 

 necessary, as the hills are cut by numerous ravines. For 16 miles before the junction of Pass 

 creek with Coo-che-to-pa creek, the former passes through a broken canon. After following 

 Coo-che-to-pa creek seven miles, the valley of Grand river is attained. 



The route follows the valley of this river 1*73 miles, then crosses the divide to Green river, 

 68 miles, and by the tributaries of the latter approaches the pass through the Wahsatch mount 

 ains. A tunnel three-quarters of a mile long is here required, the eastern approach to which 

 is by means of a grade of 125 feet per mile for 6^ miles, and a descent to the west for 5 miles 

 of 131 feet per mile. Thence westward along the valley of Salt creek for 18 miles the grade 

 is 95 feet per mile, 16 miles of which is through a rocky canon, intersected by lateral streams. 

 The route then enters the valley of the Sevier, the exploration terminating on this river, 86 

 miles further on, and 1,348 miles from Westport. 



From the western border of the State of Missouri to the Rocky mountains, 650 miles, no 

 timber suitable for railroad purposes will be found, upon which reliance can be placed. From 

 the Coo-che-to-pa Pass to the Great Basin, 500 miles, there is none available on the route, and 

 the nearest supplies on the mountains bordering the Great Basin are in latitudes 40 and 41. 



