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.
The short distances and the exciting koai’a trees, which are low to the ground with twisting and gnarly branches, make this an ideal place to hike with small children. Other beautiful native trees you can expect to see are hala pepe, ala'a, māmane, and some of the largest ʻōhiʻa trees in the area. Birds are abundant in the sanctuary, and it is not uncommon to see pueo (Hawaiian owl) soaring overhead. On clear days, the Koai’a Tree Sanctuary offers rewarding views of the Kohala coastline and the three southern volcanoes: Mauna Kea, Mauna Loa, and Hualalai. This is also an excellent spot to catch the sunset.
In the 1960s a fence was put up by foresters to protect the area, and the sanctuary reflects the forest that has rejuvenated since then. Before the fence was put up, many of the older trees within the gulch managed to escape being ravaged by destructive cattle hooves because of the steep gulch and numerous rocks. Now the Kohala Watershed Partnership has volunteer days in the sanctuary and along the 220-acre 2-mile corridor all the way up to Pu’u O Umi Natural Area Reserve. Volunteers help remove invasive fire grass, construct retaining walls, plant saplings, and construct sediment dams to protect the coral reefs along the Kohala coast.
The Koai’a Tree Sanctuary is a great place to visit if you are looking for a short hike and are interested in the plant life within Hawaiian dry forests. However, it is also the starting spot for legal access up to Pu’u O Umi Natural Area Reserve, so you can continue on up the corridor for a longer hike. You also access the summit trail for Kohala from this location.