This biodiverse park in the prairies of South Dakota is home to forests, grasslands, wildflowers, bison, prairie dogs, and elk.  Beneath all this beauty lies one of the longest and most complex caves in the world, Wind Cave.  Its name comes from the wind that blows from a small natural entrance to the cave, but its most famous feature is boxwork, the intricate and rare calcite formation found throughout the cave.  Using only 2 colors and an easy to follow chart, this design recreates the perfectly imperfect pattern in a fun hat that would look great in any colors.