The Ko’olau Range is a landform that originally formed as a single mountain called the Ko’oalu Volcano. What remains now is the western half of Ko’oalu; the original mountain has been destroyed over time. The eastern portion slid suddenly into the Pacific Ocean and now its remains lie over nearly 100 miles of sea to the northeast of the island of O’ahu. I predict that, with time, this landform will begin to be heavily eroded, as most mountains do.