Southeastern Washington and Adjacent Idaho. II 
tion of the basalt is correspondingly of a smaller degree, the rock 
often crops out upon the surface. Such rocky lands are known 
locally as scab-lands. They often occupy what appear to be for- 
mer river valleys, although they are now dry or contain only small 
streams or small groups of lakes. These valleys may be of con- 
siderable extent; the local names, “ Eight-mile Flat,” ‘“ Twelve- 
mile Flat,” etc., indicate their size. 
Owing to the porous nature of the basalt, as well as to sheets 
of clay, sand, and gravel interspersed between the successive 
layers, springs are numerous throughout the region. Oftentimes, 
wells dug merely into the soil afford a good supply of water, 
although they are usually drilled into the basalt (8). In other 
cases, as at Pullman, an abundant supply of fine artesian water 
is obtained from beds of sand and gravel between the layers of 
basalt. 
Standing above the surrounding plateau are numerous isolated 
buttes and several ranges of low mountains. These are the tops 
of lofty mountains not overwhelmed by the flood of basalt. 
Among the former, Steptoe Butte, a perfectly conical peak with 
an altitude of 3,613 feet, is a landmark to be seen for miles. 
Likewise, Kamiak Mountain, running from east to west for a 
distance of over two miles, and reaching an altitude somewhat 
greater than Steptoe Butte, is equally prominent. In some cases, 
only a few acres of the tops of buried mountains show them- 
selves above the basalt. Such a butte may be seen just west of 
Bald Butte, the culmination of a ridge of quartzite running out 
southwestward from Thatuna Hills. Tekoa Mountains, near 
Tekoa, Washington, are a low, outlying ridge of the Bitterroot 
system. They reach a height of 4,000 feet. Gold Hill, not far 
from Potlatch, Idaho, is the highest point (about 4,500 feet) of 
another group, while Cedar Mountain (4,950 feet), northwest of 
the Clearwater River in Idaho, is the highest point of a consider- 
able range known as Thatuna Hills. These buttes and mountains 
are very old geologically as compared with the basalt, and are 
well eroded and mostly forest-covered. Southeastward their 
streams empty into the Clearwater River. Elsewhere they are 
tel 
