196 SOUTHWESTERN NEVADA AND EASTERN CALIFORNIA. 
portions of the valley no animals other than a few coyotes live, and 
the oppressive silence is unbroken. Much of the valley is absolutely 
without vegetation and the adjacent mountain slopes are equally 
bare. Mesquite grows on the sand area west of Surveyors and 
Stovepipe yells and at Mesquite Spring. The upper portions of 
the alluvial slopes have here and there a sparse growth of creosote 
bush and white sage, and --nit grass cover- restricted areas around 
the wells. 
The lowest point of Death Valley within the area mapped is 
about l ; ><> feel below the sea level, but 15 miles farther south the 
depression is at least 125 feel deeper. The mountain ranges on 
either side of the valley are from r>.on<> to 8,900 feel high, and in 
consequence of this great difference in elevation the slopes are steep 
and wide alluvial cones sweep up to the mouths of the deeply scored 
canyons. The floor of the valley i- diversified by numerous hills 
and low ridges of Tertiary sediments. The pail of the valley lying- 
north of a low ridge at the head of Salt Creek i- sometimes called 
Mesquite Flat. 
A large sand dune occupies the bottom of Mesquite Flat. Most of 
the larger -and dune- are without vegetation, while some of the 
smaller one- <•_'<) fed high and 1'") feet in diameter) owe their exist- 
ence chiefly to the protecting influence of mesquite and similar 
vegetation (PI. II. AM. Death Valley is the only portion of the area 
surveyed in which sand storms endanger life. The area mapped 
a- -and contain- within it.- limit- many small areas of clay and is 
without doubt partially under water in times of excessive Hood-. In 
like manner the playa deposits mapped to the south, north, and 
ea-t of the -and arc studded with minor sand dune-. 
South of Salt ('reek the center of the valley is a loamy Hat covered 
with -alt grass. This passes gradually southward into a salt marsh, 
4 miles vide, which, according to Campbell.''' extendi about 25 miles 
south of the area, mapped. It is a dirt-brown flat, containing numer- 
ous channel- and ponds of stagnant or gently flowing salt water. 
The soil itself is heavily impregnated with salt.-, and hy fractional 
recrystallization the margin- of the water bodies are coated with 
glittering white salt deposit-. The salt-cemented -oil stands up in 
rugged pinnacles and hummock- from 6 to 18 inches high. Camp- 
bell 6 states that a specimen of this material from a point south of 
Furnace Creek has the following composition: 
"Campbell, M. li.. Bull. U. S. Geol. Survey X... 200, 1902, p. is. 
6 Loc. cit. 
