Paul Noordhoek, age 14, of Shaldon, Iowa, for his question:
What caused the Bad Lands?
No traveler could cross the Bad Lands with its steep towers, its deep gulches, its sheer wall of natural rock. It is a region where running water has eroded the earth into pits and pinnacles. The erosion has sliced through layers of colored rock ‑ rosy reds, yellows, purples and greens. To the traveler, this is a region of impassable Bad Lands, to the sightseer it is a region of scenic beauty.
The Bad Lands of South Dakota is a National Monument covering an area of 207 square miles. And South Dakota is a wonderland of scenic beauty. The young Missouri Rivers already wide and strong slices the state roughly in half from north to south. To the west stand the Black Hills, dark against the sky. The hills are not really black. Their darkness comes from the foliage of dark pines standing with their roots in rosy red earth.
There are also noble Mt. Rushmore, Wind Cave with its honeycombed brimstone formations and little Jewel Cave set with crystals of calcite. Every year a large number of visitors coma to admire these and other wonders of South Dakota.
A hundred million years ago, the region of the Bad Lands was an inland sea. Amphibians and giant reptiles waded around its shores. But the surface of the land was changing. The inland waters began to drain back to the sea. The region became a swamp land, teaming with vegetation and all kinds of strange creatures.
About 50 million years ago, the region became high, dry land. The bad of the ancient sea had been sandstone. Onto this had washed layers of colored mud and clay from the Black Hills. The area was a deep sandwich of various colored rocks, none of them strong.
Then, season by season, came the pouring rain. The water cut gullies deep into the rocks, washing out gulches and leaving steep towers. Through millions of years, the pies and pinnacles of the Bad Lands became steeper and sharper. The deeper layers of colored rocks were revealed and with them, the fossils of creatures who lived there when each layer was formed.
The Bad Lands is a great reservoir of fossils. The bones of ancient rhinos have been found there, the teeth and bones of the dread saber tooth tiger and the remains of ancient camels. Also found in the Bad Lands were the bones of little Eahippus, the three toed horse who lived there 50 million years ago.
For countless ages, the Cheyenne and the White Rivers have run eastward from the Black Hills to meet the Missouri. They and their tributaries have eroded the colored clay and the soft sandstone. To this day, every shower cuts deeper gullies in the Bad Lands. At first sight, you might think that nothing can live in this grim territory, but this is not so. There is Buffalo grass on some of the slopes, and all kinds of wild flowers that bloom in the spring flowers, phlox, wall flowers, red mallow, white, blue and purple lilies, pentstemon and yuccas. And, there are a few dark Rocky Mountain Cedars.
There is also animal life in the Bad Lands ‑ chipmunks and prairie dogs, fox, skunk and coyote. There are raccoons and rabbits, a few mule dear and a number of bobcats to maintain discipline among the tenants of the Bad Lands.