As I mentioned in the intro, the Ko’olau Mountains are one of the two major mountain ranges that make up Oahu. Compared to the Waianae Mountains, the Ko’olaus are shorter in elevation, longer in distance, and contain some of the best trails on the island.
The entire range is actually the remains of a massive shield volcano that began erupting over two million years ago, then subsequently eroded to give the mountains their strikingly dramatic appearance, like a serrated wall jutting out of the ocean. The Ko’olau Summit Trail follows the spine of the ancient volcano’s western flank, with numerous trails—some more accessible than others—feeding it from both sides of the island.
The range is crowned by many 2,000-footers, but my favorite hike goes to the tallest peak, Konahuanui, which sits at 3150 ft. It’s a challenging 7.5-mile out-and-back trail with excellent panoramas of the island. For a more relaxed time, the switchbacking Kuliouou Ridge Trail is the lightest of the bunch. It’s not as exposed as the others and has some stairs to make the 4.7-mile walk easier.
Hardcore hikers looking for an extreme challenge might be interested in thru-hiking the Ko’olau Summit Trail—an 8-day journey that’s as perilous as it is beautiful.