Hawaii Trails

Kahinahina Road, also called the Mauna Kea Access Road, Mauna Kea Hunters Road, or simply the R-1 Road, is probably Hawaii's most epic offroad trail. Beginning at the Mauna Kea Visitor Center, it forms a 36-mile loop around the rarely visited back side of Mauna Kea, connecting to the Old Saddle Road at the Mauna Kea Forest Reserve entrance. It traverses a wide variety of terrain high on the side of Hawaii's tallest volcano, from evergreen forests and rare Silversword groves to dry washes reminiscent of Arizona or New Mexico to barren red lava fields that feel like driving on Mars. Much of the route is above timberline, and several side spurs climb over 11,000 feet above the ocean below. If the weather is clear, you can see Maui and the Haleakala volcano in the distance.

The road surface is mostly rough, rutted dirt and OK lava rock, though there are rockier sections, and 4WD is required. Though not recommended for the average tourist, visitors to Hawaii with offroading experience can easily drive in the stock Jeep Wranglers you can rent at the airport. It can be combined with a drive to the summit of Mauna Kea and multiple optional side trails for a full day of offroad adventure exploring places that few visitors to Hawaii will ever see.

There are camping opportunities at various points along the trail, though it is better to lower down near the trail's western end.

Note: Hunters most often use this road, so it is recommended to wear bright colors if walking off the road. A permit is required for unlicensed vehicles but not for passenger vehicles.

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.