The forest-covered summit of the volcano consists of many cones which generated lava from its two rift zones between 240,000 and 120,000 years ago. Kohala completed its shield-building stage 245,000 years ago and has been in decline ever since. Potassium-argon dating indicates that the volcano last erupted about 120,000 years ago in the late Pleistocene. Kohala is currently in transition between the postshield and erosional Hawaiian volcanic stages in the life cycle of Hawaiian volcanoes.