Located approximately 8 miles east of the Bloomfield, this 5200-acre area is one of the most unique geological features in Indiana. The American Bottoms Area is a large basin surrounded by bluffs and ridges on three sides formed by a pre-glacier trench, which consists of approximately 100 feet of gravel, sand, and silt. What makes the area unique is that it has no surface drainage out of it, but instead utilizes two porous types of stones, Sandstone and Beech Creek Limestone to provide a natural drainage system known as the “Swallow Hole”. Four special conditions were put together to form this unusual geological event: (1) rock was exposed, (2) several uplifts with intervening short periods of stability, (3) glaciers on two sides of the area, and (4) the last the main drainage flow toward the west or south. While Bridge Creek drains directly into the American Bottoms Area, the water travels underground day-lighting at a spring draining from a rock bluff (also known as Rock Springs) near Koleen and then continuing its journey toward Richland Creek.