For Labor Day, me and my friend Graham decided to head to the north part of Hawaiʻi island and hike the trail into Pololū Valley. Pololū (meaning "long spear" in Hawaiian) is the northern-most of the seven major valleys that cut the northeast flank of the extinct volcano Kohala, which sits north of Mauna Kea. On our way, we stopped at Waipiʻo Valley, the southern-most of the seven valleys. These valleys all have very steep walls; there's a 4WD-only road down into Waipiʻo (the only way in other than by sea), but no vehicle roads into any of the other valleys.
This is a panorama I put together from a series of pictures taken at the Waipiʻo Valley overlook, at the end of the valley on its southern side. After stopping there we continued on to the town of Waimea, where we stopped for lunch at a local burger joint called The Village Burger (excellent food!), before continuing up along the road below the ridge of Kohala. The region of Kohala and the northern flank of Mauna Kea have a lot of cowboy culture, and the parking lot had some rather amusing signs:
Driving north from Waimea along the upper highway that runs below and parallel to the Kohala ridge, there's a pretty dramatic demonstration of the rain-shadow effect. Kohala is an old, extinct volcano, the north-east side of which collapsed in a land-slide that left it with a peak ridge running north-west to south-east and created the dramatic cliffs that end so abruptly at the sea as you saw in the first picture.
The prevailing winds in the Hawaiian archipelago come from the north-east, so most of the humid air condenses into rain as it encounters the north-east side of Kohala; very little makes it over to the west side (which is also why Hilo on the east side is wet and Kona on the west is dry). The road runs mostly parallel to the ridge and the line between wet and dry, as you can see in these pictures. As you drive north, on your right you have this view, looking up towards the ridge:
And on your left, running down to the sea on the west side, you see this:
(That's Kawaihae harbor on the shore there. I'm guessing the extreme haziness in the air on this side is vog from Kilauea being blown up around the west side of the island.)
Another cool sight you get to see on a clear day like we had is the vast bulk of Maui rising in front of you. I was actually quite surprised at how different Mauai appears from the summit of Mauna Kea, as that's usually the only place I see it from. The ʻAlenuihāhā channel between Hawaiʻi and Maui is only about 30 miles across, so it's not that far away.
This actually turned out to be a lot more photos of the drive up than I thought, so I'm going to put the photos from when we actually got to Pololū Valley into their post, hopefully up tomorrow. A hui hou!