Heidi's Plaque is located in Palolo Valley on the island of Oahu. It is set into a boulder resting at the top of a waterfall in Waiomao Stream. The waterfall is the second of three waterfalls on the trail leading to the rim of Ka'au Crater - an extinct volcano that is now a wetland marsh area.
 

What to Expect

The hike to Heidi's plaque at the top of the second waterfall is not difficult. The trail is well-defined, but is uneven - crosses roots, rocks, water pipes, and fords the stream several times. Aside from two sections that require climbing (at the first and second waterfall), the trail in general has an easy grade as far as the second waterfall. Beyond that, it gets steep, gaining nearly 1000 feet in elevation within ~1/2 mile, and requiring the use of your hands much of the way up.
 
 
Conditions are often rainy. Be prepared to get your feet wet and muddy. Also be prepared for sun - sun block and a hat can't hurt, especially if you are going all the way to the top. There is no cover on the ridge above the third waterfall - just excellent scenery.
 
 
The top of the second waterfall is a perfect place for a picnic, or even BBQ. Bring plenty of water. The hike to the second waterfall and back can be completed in 2-3 hours without difficulty. Add an additional 2-4 hours for a complete round-trip to the peak at Palikea.
 
 
To the Valley:

H-1 East

Off at 6th Street

Head Towards the Mountains (Mauka) - 2 blocks to Waialae Avenue

Right on Waialae to 10th Street

Left on 10th Street and into Palolo Valley

~ 1 3/4 miles up 10th Street the road forks into Waiomao Road

Right onto Waiomao Road
 
 
To the Trail Head

Stay on Waiomao Road to the end. Do not turn off of the main route. The road curves, narrows, passes a Buddhist Temple, continues into the valley, continues curving, continues getting narrow. After about a mile you will be running out of road - come around a curve and find a broad dirt shoulder on the right side of the road across from a house with a carport. Park on the shoulder.
 
 
Continue walking up Waiomao Road. You will immediately come to a fork with a "Peace Pole" at the vertex (a white post painted with "May Peace Prevail On Earth"). Take the left fork. Ignore the "NO TRESSPASSING" signs, but stay on the road. You will shortly be greeted by two dogs. They have big barks, only seven legs between them, and sweet personalities. (They are also getting on in years and might not be there to greet you). Do not be discouraged by them - they are announcing that you have found the trail head.
 
 
Just past the dogs is a chain link fence with official-looking signs about tresspassing. Go around the chain link fence to the left. An access road heads straight ahead past a pump station. Follow it.
 
 
To Heidi's Plaque

When in doubt, continue heading up the valley. Follow the road to an exposed water pipe on your left. The trail snakes down steeply around the pipe and descends towards the stream.
 
 
Cross the stream and pick up the trail on the far side where it begins to ascend rightward. The trail curves up a rise then heads leftward, passes an abundant growth of ginger and several old trees, then descends to the stream again.
 
 
Cross the stream and pick up the trail on the far side where it skirts the stream bank. As the stream curves towards the right, the trail intersects it again.
 
 
Cross the stream and follow the trail up a relatively steep grade. The trail leaves the valley floor here and contours the valley's west slope following an old water pipe. You have come approximately 1/4 of a mile at this point.
 
 
The forest opens up to views of the higher reaches of the valley and the peaks of the Koolau Range. Continue upwards following the water pipe.
 
 
After approximately 1 mile, the trail comes upon a metal plate and an old water tunnel closed off with a heavy steel door. Just past these landmarks, to the left, is a rock formation which is the continuation of the trail. The trail leading downwards to the right will take you to the stream and the base of the first waterfall. Its a nice detour.
 
 
Climb up the rock formation. Test the ropes fastened there before putting your weight on them, or just use the handholds in the rocks. The trail continues at the top with a short descent to the top of the first waterfall.
 
 
The trail continues on the far side of the water fall. Cross over the rocks and pick your way through the ti, ginger, and hau trees. Within five or ten minutes the trail will enter the stream bed again. You are now at the base of the second waterfall. Heidi's Plaque is at the top.
 
 
Facing the waterfall at the pool, you will see the trail climbing up the right side of the valley. There are plenty of roots, branches, and hand holds to get you up and back down. As you reach the top of the waterfall, a large boulder blocks the trail. Climb over the boulder and you have reached the top.
 

You can see how the trail continues from here. If you wish to follow it, it will quickly bring you to the base of the third waterfall, which slopes up the west wall of the valley. The trail follows the waterfall. There are ropes and carved steps to assist you, but it is steep and can be slippery. Be careful and go only as far as is comfortable. Remember that its easier going up than down.
 
 
At the top of the waterfall, climb up the trail to your right (heading up-slope). Again, there are ropes to assist you. A short, steep climb brings you out on the top of the ridge. Ka'au Crater, a bowl-shaped swamp, is now visible. Theres only one way up from here. The trail ends at the peak - Palikea - ~2400 feet in elevation.

by Jim Niermann