GA>sETT.J GEOGRAPHY GRAND CANON OF THE GUNNISON. 427 



At the mouth of / creek : 



At level of river est 7, 1 00 



Top of the gneiss a 8, 000 



Height of caSoQ in gneiss 900 



Top of plateau, east side / creek a 9, 000 



Height of caiion wall 1, 900 



Top of plateau, west side / creek a 8, 900 



Height of caiiou wall 1, 800 



At station 77 : 



At level of river h 6, 800 



Top of gneiss, north side of river a 8, COO 



Height of caiion in gneiss 1, 800 



Top of plateau, north side of river, (station 77)" ad, 800 



Height of caiion wall 3, 000 



Top of plateau, south side of river t 9, 400 



Height of caiion wall 2, 600 



At station 80 : 



At level of river , est 6, 200 



Top of gneiss, northeast side of river est 7, 200 



Height of canon in gneiss .- 1, 000 



Top of plateau, northeast side of river, (station 80) a 8, 500 



Height of canon, northeast side 2, 300 



Top of plateau, southwest side of river ^8, 050 



Height of caiion 1, 850 



At mouth of Smith's Fork : 



At level of river est 5, 600 



Top of plateau, east side of river, (station 81) a 6, 437 



Height of caiiou, east side , . . 837 



Top of plateau, west side : t 6, 700 



Height of canon, west side 1, 100 



At mouth of North Fork : 



At level of river a 5, 400 



Top of plateau, east side, (station 82) a 5, 800 



Height of caiion, east side 400 



At foot of caiion: 



At level of river „ a 5, 125 



Top of plateau, (station 83) , a 5, 750 



Height of caiion 625 



The North Fork of the Gunnison is its largest tributary. It drains 

 nearly all of that part of the Elk Mountains west of Rock Creek, which 

 consist principally of the isolated groups which have been described 

 earlier in this report, and of most of the southern slope of the great 

 plateau. Those of its branches which drain the mountains have no 

 valleys worthy of mention within the mountains, and outside of them 

 are in close caiion. The main stream heads against the divide between 

 the Grand and Gunnison Elvers, in longitude 107° 30', and drains a 

 very broad valley. It enters a caiion in the rolling plateau country, in 

 latitude 39^.4', and in this caiion receives the branches known as Anthra- 

 cite and Coal Creeks. This caiion continues as far down as the longitude 

 of station 39, where the stream comes out into a valley, which is very 



Note. — h, barometric maasurement ; a, aneroid measurement ; t, trignometric meas- 

 urement; est, estimated. 



