Skyline Road Loop

If you don't have time to drive the full Kahinahina Road (R-1) loop around the backside of Mauna Kea but still want to have an incredible offroad adventure above the clouds on the side of a Hawaiian volcano, check out Skyline Road in the Mauna Kea Forest Reserve. This moderate four-wheel drive road takes you high above timberline, over 11,000 feet, into a stark volcanic wasteland that feels like driving on Mars.

Skyline Road (signed on the ground as R-10) begins a few miles up R-1 and climbs steeply up the mountainside until reaching a terrace with a short side spur out to an overlook at a ring-shaped stone wall. After checking out the overlook, you can either keep going straight on R-10 or turn left on an unmarked road to begin the loop to the mountain's upper reaches. Following the loop road, you'll wind up the mountainside toward a cluster of large cinder cones. As you climb higher, the sparse desert vegetation gives way to a desolate plain of fine red lava rock, surrounded by cinder cone peaks with the main summit of Mauna Kea looming above. A short spur off the main loop leads to the highest point at a saddle with spectacular views looking back down the mountain and over the sea of clouds that usually surrounds it.

Back on the main loop, the road crests a rise and then descends steeply through a field of larger lava rocks with rare Silversword plants growing among them. This is the roughest portion of the trail but is still easily passable in a stock rental Jeep from the airport. Before long, the loop road meets back up with R-10 and completes a full loop back to where you started.

While people may occasionally camp along this road, it is not really suitable for it, and there are no established campsites.