When looking at the crater of Mount Waialeale, think of Mount St. Helens and its eruption in 1980. Unlike Hawaii volcanoes such as Diamond Head or Koko Head whose craters are best viewed from above, Mt. Waialeale erupted sideways much like Mount St. Helens. In fact the entire eastern side of the mountain blew out in an eruption eons ago. The pyroclastic flow helped form many of the valleys that now make Kauai so beautiful.
A common question is why Mount Waialeale is the wettest spot on earth averaging more than 460 inches of rain each year at the summit. The answer is three-fold. Its northern position relative to the main Hawaiian Islands provides more exposure to frontal systems that bring rain during the winter. It has a relatively round and regular conical shape, exposing all sides of its peak to winds and the moisture that they carry. Finally, its peak lies just below the so-called trade wind inversion layer of 6,000 feet (1,800 m), above which trade-wide-produced clouds cannot rise.
The views of Mount Waialeale and the valley below from this viewpoint are, in my opinion, superior to the views you get by helicopter. This final stop puts a crowning gem on the fine 4x4 tour.
