OUR NATIONAL PARKS 
577 
from vandalism, nnantliorized explora- 
tion, and spoliation. For this reason lo 
of the monuments that are situated 
within national forests have been placed 
under the supervision of the Secretary 
of Agriculture, one under the Secretary 
of War, and the remaining 17 under the 
direction of the Secretary of the Interior. 
Of the national monuments under the 
administration of the Secretary of the 
Interior the most striking are the Natu- 
ral Bridges and Rainbow Bridge in 
Utah, El Morro in New Mexico, the 
Muir Woods in California, and the Pet- 
rified Forest in Arizona. 
The Natural Bridges Monument, 
which is located in southwestern Utah, 
includes the three largest natural bridges 
that have been discovered. The Augusta 
Natural Bridge, the largest of the three, 
is a splendid arch of solid sandstone, 
measuring 335 feet from wall to wall 
and having below it a clear opening of 
357 feet. It is more than three times as 
high and has twice the span of the cele- 
brated natural bridge in Virginia ; it 
would overspan the Capitol at Washing- 
ton and clear the top of the dome by 51 
feet. 
The Rainbow Bridge is near the south- 
ern boundary of Utah, and is unicjue in 
that it not only forms a symmetrical 
arch on its under side, but presents also 
a curved surface above, and this resem- 
bles in shape a rainbow. It is 309 feet 
above the surface of the water and has 
a span of 278 feet. 
Illustrations and full descriptions of 
these bridges have been published in 
recent numbers of this Magazine.* 
El Morro is an enormous sandstone 
rock, in western New Mexico, that has 
been eroded in such fantastic forms as 
to give it the appearance of a great 
castle ; hence the origin of its Spanish 
name. A small spring of water found 
existing at the rock made it a convenient 
camping place for the Spanish explorers 
of the 17th and i8th centuries, who 
carved on its face many inscriptions that 
are of great importance to the early his- 
tory of the southwest. As there has here- 
*Described in the NatioxaIv Geographic 
Magazine. November, 1911, "The Great Rain- 
bow Natural Bridge," by Joseph E. Pogue. 
tofore been no local custodian, the rock 
is exposed to vandalism and the inscrip- 
tions are threatened with destruction by 
thoughtless visitors. 
The Muir Woods National Monument 
is situated near the city of San Francisco 
and includes one of the most noted red- 
wood groves in the State of California. 
The tract contains many trees more than 
300 feet high, with a diameter of 18 feet 
or more at the butt. It was presented to 
the United States by William Kent. 
The Petrified Forest in Arizona con- 
tains a large c[uantity of petrified trees, 
none of which stand erect in place as do 
many of the petrified trees in the Yellow- 
stone National Park. The most promi- 
nent specimen is a great trunk, which 
forms a bridge across a canyon 45 feet 
in width (see page 572). 
The other national monimients under 
the super v^ision of the Secretary of the 
Interior are as follows : The Devils 
Tower, a landmark in Wyoming; Mon- 
tezuma Castle, Tumacacori, Chaco Can- 
yon, and Gran Quivira in New Mexico ; 
and Navajo in Arizona, prehistoric or 
Spanish ruins ; Pinnacles in California, a 
group of spirelike formations underlain 
by caves ; Mukuntuweap in Utah, a pe- 
culiar and beautiful gorge; Shoshone 
Cavern in Wyoming and Lewis and 
Clark Cavern in Alontana, limestone 
caves of great beauty ; Sitka in Alaska, 
an area containing some of the finest to- 
tem poles known ; Colorado in western 
Colorado, an area of eroded monoliths 
similar to the well-known Garden of the 
Gods near Colorado Springs. 
The national monuments administered 
by the Secretary of Agriculture are as 
follows : Lassen Peak and Cinder Cone 
in California, volcanic areas of great 
scientific interest ; Gila CliflF Dwellings 
in New ^Mexico and Tonto in Arizona, 
prehistoric ruins ; Jewel Cave in South 
Dakota and Oregon Caves in Oregon, 
limestone caverns of considerable ex- 
tent ; Mount Olympus in Washington, 
the summer range and breeding ground 
of the Olympic elk ; Wheeler in Colo- 
rado* and Devils Post Pile in California, 
*See National Geographic Magazine, Sep- 
tember, 1909, "The Wheeler National Monu- 
ment." 
