If driving on Kamehameha Highway, from Haleiwa heading towards Sunset Beach, turn right on Pupukea Road (at Foodland). Continue up the road, past the Pu`u `O Mahuka Heiau, until the road ends at a gate and Camp Pupukea. Park below the Boy Scout camp along the road. Now Proceed on foot down the dirt road. The Kaunala Trailhead will be on your left about 3/4 mile down.
Proceed along the dirt road past the Boy Scout camp, following the route of the old Pupukea-Kahuku Trail. Go through a locked yellow gate and enter Kahuku Range, an Army training area. Sign in at the hunter-hiker check-in mailbox on the left. Reach a junction. Keep left on the main road, which has become paved. Shortly afterward reach a signed junction at the edge of a grove of paperbark trees. Turn left on the wide Kaunala Trail. (The paved road curves to the right and is the return portion if you decide to make a loop hike.) Immediately take the left fork to contour around a hill. Descend gradually on four switchbacks through a eucalyptus forest. Ignore trails going straight down the side ridges. Cross over a side ridge and begin to contour into and out of several gulches. Descend into the second gulch on two short switchbacks and cross tiny Paumalu Stream. Cross over a side ridge in a paperbark grove. Descend gradually through several more gulches. After crossing a small stream, climb gradually to an open area covered with uluhe ferns. Ascend the right side of a side ridge through native koa and `iliahi (sandalwood) trees. Contour briefly and then switchback once. Reach the end of the Kaunala Trail at a signed junction with a gravel road in a grove of paperbark trees. To make a loop hike, turn right on the road and climb steadily along a wide ridge past native `ohi`a and koa trees. Reach a flat, cleared area and then descend steeply, but briefly to go through a locked gate. Presently reach a junction with the original paved road near a stand of Cook pines. Turn right on the road. Descend gradually along an up-and-down ridge passing a covered picnic table on the right. Reach the familiar junction with the Kaunala Trail at the far edge of the paperbark grove. Retrace your steps to the Boy Scout Camp.