On the surface, much of Utah is a desert. Wind, water, and time cut through rock to reveal a history of shifting ecology.  Great inland seas that repeatedly filled and emptied the landmass left their signature deep within the terrain.  Any observer descending into the canyons will notice the colorful change from one period to the next. Each layer is a time capsule showing the climate and biota of the day.  Global forces impart a variety of factors into these diverse bands, but the periodic flowing of the  inland sea gives the landscape its most spectacular elements.