EASTERN SECTION - Yellowstone Treasures - page 173

The road passes along the northern edge of Buffalo Bill Reservoir, crosses the Shoshone
River, and then passes the little town of Wapiti, named after the wapiti (elk). Soon after the
sign about the local geology, you'll enter an area covered by what geologists call the Absaroka
Volcanics. Around 50 million years ago, about a dozen major volcanic centers spread lava and
tephra over a huge area from beyond the northwest corner to well southeast of Yellowstone
Park (see the map of the Absaroka Volcanics, page 159 ).
Look at relatively low Jim Mountain to the north, where you can see the edges of the old
volcanic lava flow layers. In the distance beyond Jim Mountain, you may catch a glimpse of
high Dead Indian Peak, another of many mountains made of lava.
West of Wapiti, you'll be entering America's first national forest, the Shoshone National
Forest, created in 1891 and called at that time the Yellowstone Timber Land Reserve. It was
set aside to be a cushion of protection east and south of Yellowstone.
As you drive west, you'll begin to see the fantastic rock formations or hoo-doos this road
is famous for. About a mile (1.6 km) into the national forest, on the left (south), is the first of
many named hoodoos, Laughing Pig Rock.
On the north side and almost perpendicular to the road is the Chinese Wall, actually a
dike, a thin vertical sheet of hardened magma. In 4 to 5 miles (6-8 km), you'll see Hanging
Rock, hanging almost over the road. Less than 1 mile (1.5 km) from this is Goose Rock at
right center on the cliff top. In the same turnout area is the Holy City. Many equally fantastic
shapes may inspire you to name them yourself.
One of the most easily recognized hoodoos is Goose Rock.
What's a Hoodoo?
To geologists, a hoodoo is a standing column or odd shape left when sedimentary rock has
eroded unevenly. Here the process of making hoodoos began when the lava flows and te-
phra in the extensive Absaroka Range volcanic mountains were eroded. Rain sometimes