This habitat area represents an open riparian hillside.  The word “riparian” refers to being situated on the banks of a river or stream where trees and shrubs provide nesting materials, food and shelter for wildlife. They create shade that helps control water temperature and prevent erosion.  They also offer a source of organic matter and woody debris that filter into the waterway and provide beneficial nutrients. Riparian habitats are important biofilters. They can protect aquatic environments from excessive sedimentation or pollution caused by erosion and runoff. They are rich in biodiversity. The riparian hill is a large area of the garden that has distinct features as part of its landscape which include the shell midden, the seasonal creek, and a vegetative swale. Here you will find such tree and shrub species as bigleaf maple (Acer macrophyllum), vine maple (Acer circinatum), black cottonwood (Populus trichocarpa), red elderberry (Sambucus racemosa), red osier dogwood (Cornus sericea), red flowering currant (Ribes sanquineum), Pacific wax myrtle (Myrica californica), and red huckleberry (Vaccinium parvifolium).