The state park is located on at the end of Iao Valley Road (Highway 32). The Iao Needle (Kūkaemoku), a landmark in the state park, is a vegetation-covered lava remnant rising from the valley floor or above sea level. The needle is a sharp ridge that gives the appearance of being a spire when viewed end-on. The needle is an extension of and surrounded by the cliffs of the West Maui Mountains, an extinct volcano. There is a short trail (Iao Needle Lookout Trail and Ethnobotanical Loop) to a windy overlook.