Pretend you are watching a movie about the shaping of this
landscape over eons of time. The Earth's surface recurringly
rises and falls, crumbles, and blows away. The higher the land
rises, the faster it is carried away by wind and rushing water,
dictated by the constant pull of gravity. You see buckling,
folding, and cracking of the surface caused by tremendous
uplifts from deep within the Earth. This is matched by equally
dramatic forces of erosion at work on the surface. The last
quarter of this imaginary movie depicts the events that show up
today in the rocks of Colorado National Monument. The
Uncompahgre Highland rises to mountainous heights, then is worn
down over millions of years to a nearly level plain. (These
ancient crystalline rocks - granite, gneiss, schist - which were
at the core appear today in the canyon floors.) Great bodies of
water follow, depositing layer upon layer of soft, sedimentary
rocks as distant mountains give themselves up, grain by grain,
to be reformed. Becoming entombed withi