54 GEAVEL AND PLACER MINING IN ALASKA. [bull. 26 
conditions of erosion have produced surprisingly low gradients in tt 
streams. Table 7, below, gives the grades of streams in the gol< 
producing districts of the north. For the sake of showing the defee 
of Alaska in the important requirements of grade, the lowest figure ] 
the table gives what is frequently referred to by gravel miners i 
" sluice-box grade." If the sluice boxes are carried on a grade lowc 
than 6 inches to the 12-foot box, the gravel can not be economical] 
moved through it except by employing an excessive quantity of wate 
By comparing the sluice-box grade with those of the various Alasfe 
creeks, it becomes evident that in nearly every case the material, eittl 
before entering or after leaving the tail sluice, must be artificial] 
elevated in order that the sluice may have sufficient grade. Tl 
various devices in use for accomplishing this elevation will be di 
cussed under proper headings. 
Table 7. — Stream grades along important sections of their courses. 
Average fall 
Juneau district: in feet per mi 
Gold Creek 2! 
Nizina district: 
Dan Creek 2( 
Atlin district: 
Pine Creek { 
McKee Creek 41 
Klondike district: 
Eldorado Creek i 
Bonanza Creek 
Gold Run J 
FORTYMILE DISTRICT: 
Wade Creek ' 
Chicken Creek 
Walker Fork f 
Eagle district: 
American Creek 
Circle district: 
Deadwood- Creek 
Mastodon Creek 
Mammoth Creek 
Eagle Creek 1 
Fairbanks district: 
Fairbanks Creek 
Chatham Creek 2 '' 
Cleary Creek "| 
Pedro Creek 'j 
Rampart district: 
Little Minook Creek • 
Hunter Creek 
Nome district: 
Anvil Creek j ' 
Glacier Creek 'j 
Dexter Creek ■ • 
