The white and red areas in the map below indicate the highest elevations that form the watershed boundary (divide). Looking north (downstream), stream trails are evident in dark green, approaching the confluence with the river. The light blue area is the REOstone Quarry, a man-made, rock mining alteration. This is why its elevation is so much lower. The gradient from higher to lower elevation provides the transport of water, soil and nutrients throughout the watershed.
In the soils map of the WE story, we explain the value of specialized soils transported from steep slopes throughout the bottomlands of the watershed. Metro Codes restricts building on steep slopes with sensitive soil.