TOPOGRAPHIC FEATURES OF THE DESERT BASINS. 35 
Goldfield Basin and about 600 feet above that of the Big Smoky. There is another 
divide at about the same elevation in a gap leading into the Clayton Basin. Both of 
these divides are believed to be pre-Lahontan and the Basin is thought to have been 
always inclosed. It has an area of 330 square miles and contains a small playa of 
usual character. 
THE DIAMOND BASIN. 
The Diamond Valley proper is a narrow north-south trough stretching north from ~ 
Eureka, Nev., between the Sulphur Springs and Diamond Ranges. In itself it has 
an area of less than 1,000 square miles, but. into its southwest corner discharges the 
remnant of a former great drainage system which drained the southern portion ofthe 
topographically poorly-defined region mentioned on page 16. The area of this 
drainage system aggregated 1,870 square miles and included the present Kobeh, Dry, 
and Monitor Valleys, the latter extending south to the north end of the Ralston Valley 
(Armagosa drainage system) near the old town of Belmont. Most of this drainage 
system is still essentially open, though never fully occupied by water. Storm waters 
occasionally fill part of it, but seem never to reach the Diamond Valley itself. In 
many places, especially in the southern end of the Monitor Valley, low and recent 
alluvial dams have been built and have caused the formation of local playas and 
marshes. None of these have any present importance. : 
The deepest depression of the Diamond Valley contains a very saline marsh or 
playa carrying a body of common salt of unknown extent and character. The lowest 
outward pass is Railroad Canyon at the northeast corner and leads into the Hunting- 
ton River and thence to the Humboldt. This pass is now about 275 feet above the 
Diamond Valley salt marsh and it is uncertain whether it ever served as a channel 
of discharge. The writer inclines to the opinion that it did, but that the discharge 
was by overflow and occurred only during the maximum of the lake expansion. A 
long subsequent history as an independent valley seems very probable and is directly 
indicated by traces of old strand lines on the walls of the valley. In this report the 
valley is classed as landlocked and its area is not included in that of the Humboldt- 
Carson Basin. 
The present drainage area tributary to the Diamond Valley playa is perhaps 900 
square miles. The Lahontan period area was 2,800 square miles. 
THE RAILROAD VALLEY. 
The Railroad Valley is the largest of the inclosed troughs of Nevada and lies just 
southeast of the geographical center of the State, between the White Pine Range to 
the east and the Pancake Mountains to the west. The former range is one of the best 
defined of the Great Basin and, being high and continuous, it has formed a permanent 
divide between the Railroad Valley and the drainage of the Colorado River. The 
Pancake Mountains are much lower and less well defined and are crossed by several 
fairly low passes, through one of which (Twin Springs Pass) the Hot Creek Valley 
still drains into the Railroad Valley. West of the Hot Creek Valley is the Hot Creek 
Range, for the most part high and continuous, but cut about its middle by the canyon 
of the Hot Creek, through which comes the drainage of the southern portion of Fish 
Spring Valley, lying still farther west. The northern portion of this valley is now 
cut off by a low alluvial divide, but this is almost certainly very recent. Hot Creek 
Valley has also two other tributaries—part of the Little Smoky Valley from the north 
and part of the Reveille Valley from the south. The former is cut by an alluvial 
divide, north of which the drainage goes to the Gibson Valley, as discussed on page 17. 
This divide is believed to be pre-Lahontan and to have been a permanent parting 
between the Lahontan and Railroad Valley drainages. Reveille Valley is cut into 
three portions by two alluvial divides, the northern portion draining into the Hot 
Creek Valley, the southern portion into the Kawich (see p. 36), and the middle por- 
