Hicks on Irrigation of the Niobrara Valley. yi 
300 miles it falls 3,700 feet, or 12^ feet to the mile. This is 
the average slope, but in some places it descends much more 
rapidly. 
The upper portion of its valley is excavated in the loose fria- 
ble strata of the newer Tertiary. It is accordingly a broad 
shallow trough with gentle slopes rising to the adjacent table- 
lands which are some 300 feet above the river. The serpentine 
course, the grassy slopes, and the clear swift water, all contrib- 
ute to impart a peculiar charm to this region, in marked contrast 
to the rugged features of its lower course. In the vicinity of 
Valentine, in Cherry county, it is still flowing between walls 
of Tertiary age, but the rock is more compact and stands up in 
bold cliffs to the bight of 400 or 450 feet. The broad valley is 
reduced to a gorge or canon which continues to a point some- 
what eastward of the looth meridian, where the softer Cretaceous 
rocks yield more readily to aqueous and atmospheric erosion.- 
From this point to its confluence with the Missouri river, the 
valley is of considerable breadth, and is bounded by moderate 
slopes. 
The Niobrara is an interesting stream throughout its whole 
course. For the first hundred miles from its mouth the geolo- 
gist finds the peculiar chalky rocks of the Cretaceous period, 
with their numerous and very interesting fossils. The Tertiary 
rocks along its middle and upper course contain the relics of a 
mammalian fauna unsurpassed in richness and variety. Gen- 
eral Warren has stated that the Niobrai"a flows lengthwise upon 
the back of an anticlinal fold. This statement I have not per- 
sonally verified, but, whether true or not, certainly enough is 
true of this river to make its exploration unusually fascinating 
to the geologist. 
The botanist finds in the valley of the Niobrara a flora quite 
unique for Nebraska. Great pines wave their branches where, 
according to any published map of the distribution of pines, 
none of them ought to be found. A remarkable eastward ex- 
tension of the Rocky mountain pine (Pinus ponderosa) clothes 
the banks of the Niobrara and its tributaries with an evergreen 
fringe. 
The lover of the picturesque is delighted with the wild and 
varied scenery of the canons along the middle course of the 
