The Koai‘a Tree Sanctuary is a 13-acre preserve along Kohala Mountain Road that is a smaller part of a larger 2-mile riparian corridor managed by the non-profit Kohala Watershed Partnership. The sanctuary has a network of short trails, and the outer interpretive loop is only three-quarters of a mile long. A fence was built around the tree sanctuary in the 1960s, which has helped the tree forest thrive. Koai'a Tree Sanctuary was a prime area to set-up a tree sanctuary due to its' location on a steep gulch, which made it difficult for ungulates and cattle to trample the area, and introduce invasive species.

This tree sanctuary is a common home to the koai’a tree as well as other native trees such as:  hala pepe, ala'a, māmane, and ʻōhiʻa. All of the native trees within the sanctuary makes the area a beautiful place to hike and soak in nature. Koai'a Tree Sanctuary also offers breathtaking scenic view points to see the Kohala Coastline, Hualalai, Mauna Kea, and Mauna Loa.