20 BULLETIN 54, U. S. DEPARTMENT OF AGRICULTURE. 
little basins are indistinguishable and never more than a few feet in height. A very 
slight increase in rainfall would be sufficient to flood and drain them and wash their 
salt back into the Great Salt Lake. 
The present area of the Great Salt Lake Basin is perhaps 25,000 square miles. Includ- 
ing the Great Salt Lake Desert and the other.similar areas of local playas and marshes, 
but excluding the basins cut off by real though recent divides, the area is 33,760 
square miles. Including former tributaries, now the Steptoe and Ruby groups, 
and the White Valley, Rush, and Cedar Basins, the area is 42,300 square miles. 
THE STEPTOE BASIN. 
During the Lahontan period one of the main tributaries of Lake Bonneville headed 
between the Egan and Schell Creek Ranges, well south of the thirty-ninth parallel, 
flowed northward through the great trough of the Steptoe and Goshute Valleys, 
crossed the Toano Range and entered Lake Bonneville east of the present railroad 
station of Cobre. Since that time alluvial deposition, probably assisted by local 
uplift, has barred the pass in the Toano Range and cut off the Goshute Valley from 
discharge. At the same time alluvial damming and stream decay have broken the 
former through-flowing stream into a score of separate basins, each with its local 
playa and each separated from the other by low and indistinguishable divides. The 
whole valley has become an area of practically no drainage and no point or points of 
considerable concentration can be distinguished. This early drainage line still 
receives the insignificant discharge of what was once a considerable stream from the 
- Antelope Valley, and it once received also the drainage of the Ruby group about to 
be described. The area of the Steptoe, Goshute, and Antelope Valleys with their 
tributaries is 3,930 square miles. Adding the Ruby group, the total becomes 6,590 
square miles. 
THE RUBY GROUP OF BASINS. 
The Ruby group lies on the crest of the Bonneville-Lahontan divide, south of the 
Clover group already discussed and between the Ruby and Egan Ranges. It con- 
sists of the Ruby Valley to the north, with two parallel north-south valleys, the Butte 
and the Murray ! lying south from it and formerly tributary to it. The deepest 
depression of the Ruby Valley proper les at its western edge under the steep slope 
of the Ruby Range and contains Ruby and Franklin Lakes. Eastward from this de- 
pression the valley rises very gradually toward the low gap of the Goshute Pass be- 
tween the Egan and Pequop Mountains. It is reasonably certain that the Ruby 
Valley previously discharged through this gap into the Goshute Valley and thence 
to Bonneville. The topography of the pass is complicated by alluvial deposition 
and apparently by recent and local movement, and it is not possible to determine | 
with assurance whether the Ruby Valley of the Lahontan period had an unresisted 
drainage into the Goshute Valley or contained a lake which overflowed thereto over 
a permanent dam. The writer has not found conclusive signs of lake occupation in 
the Ruby Valley and hence inclines to the former opinion. In either case the valley 
lacks interest from the present viewpoint. 
Of the southern tributaries of the Ruby Valley, the Butte Valley is confined only 
by a low and inconspicuous divide across its northern end. This divide is alluvial 
and probably very recent, and there can be little question of the previous free 
drainage of the valley toward the north. It contains a rather poorly developed playa 
with an area of approximately 12 square miles. The Murray Valley is separated 
from the Ruby Valley by divides of similar character, but higher and better defined. 
They too are believed to be post-Lahontan, and the earlier outward drainage is be- 
1 This valley is known locally as Long Valley, but there being numerous other Long Valleys in the Great 
Basin, and this name being in general use for another basin (see p. 29), it is impossible to retain it here. 
