Wilderness style backpacking on the big island of Hawaii (only hike or kayak access)
Mileage: 19 miles* round trip, in and out.
Elevation Gain/Loss: 1 x 1200ft gain going in, 2x 1200 ft going out*
Management agency: Hawaiian Dept of Forestry
Fees: $19/night
* assumes leaving a vehicle at Waimanu Arts for an additional 1200 ft elevation gain and $15/night
A long planned trip to see my parents allowed me to plan an overnighter …. and the "Big Island" has a classic trail nicknamed the "Z" trail leading to the unspoiled Waimanu valley. Been here before but with a little too much gear and not enough water, so this was a UL rematch. I checked for a campsite against openings online in hawaiian state forestry services website at $19/night. This is a tough trail due to elevation changes, lava rock, and ever-present heat + humidity, everyone suffered a bit but a small price to pay for seeing a slice of undisturbed Hawaii.
The hike is 19 miles, in and back, if leaving a vehicle with Waimanu art works for (ouch) $15/night. There is a
shuttle bus around the island but it only runs by a couple times per day with an even longer hike from the bus stop.
First stop is the Waipio valley, with a scenic lookout, before the trail starts for the Waimanu. Lookout over Waipio
Even before the hike starts, I shared my way down a steep slo-mo single lane 4WD with vehicles. The photo doesn't do justice – bring hiking poles!! It's a hike to start the hike …
… as Hawaii does not recommend vehicles be left in the Waipio valley (lots of break-ins on the islands).
Nice river at the bottom but yes it will need to be crossed …
Sharing the beach with kitesurfers ..
The speed of the water over rocks picks up a bit at the only crossing; usually OK unless it floods:
Then across black sand beaches and beachgoers And their dogs. The sand gets into everything and even young women in bikinis only momentarily distract me from the pain as wet sand starts rubbing my feet raw.
Just think of it as a pedicure ….
An hour plus a sock change, It's only now the official "Z-trail" hike starts
Going up the 1200 ft Z-trail is no picnic, with increasing highstepping of lava rocks needed … 
Besides an initial climb of 1200 ft (where the land sequence of the Kevin Costner film "Waterworld" was filmed) with thigh-busting lava steps, followed by about 12 major gulches with some minor ups and downs makes this a killer hike. The shape gives it it's namesake "Z".
Still there's some nice views of the Pacific..
Going into a gulch, sometimes there's a spring or even waterfall with a deep bathing pool.
Forgot my swim trunks so I will need to redo this hike in the near future.
Still a chance to cool down my feet
The only way for the public to enter is hike or kayak, though Hawaiian trail crews and emergency workers can use the off-trail helipads.
Coming down to Waimanu valley itself, a cooling rain started to fall intermittedly, but no rain gear needed as I needed to cool off.
After this the trail gets slick with soil and downed leaves. Forgot my leather gloves and paid for it with a nasty gash to my hand. Bring hiking gloves. With rain threatening and the clouds darkening the sky, I set up camp quickly… 
the rain was start and stop until the sun fell, then started continuously until I fell asleep, taking note of any leaks on my
seam-sealing job. The campsites were full of mostly young couples but also a group of young people. Not like last time when I camped with some hawaiian kayakers at the end of their weeklong sea circumnavigation of the big island. This time I almost felt like I was intruding.
Stoveless trip… facing dawn with cold coffee #2 (#1 was a Starbucks doubleshot espresso)
Valley floor with waterfall..
Going up 1200 ft again and this time the view was sunny …
Along the trail, a sunny view of the Pacific facing eastward …
Shortly after a young couple zoomed past me with fully loaded Ospreys…
Did I mention at my mid-40s, I was the oldest person on the trail?
Going down 1200 ft and wishing for hiking poles (see Z trail pic above).
Going back up Waipio in the heat of the day for 1000ft, a very steep "afterhike … hike" 
Ran out of liquids just prior to this so it was a sufferfest
Sign is at the end of the afterhike hike … 
… but there's another 1/2 mile over a hot road if leaving a vehicle but a few more miles to the bus stop however – pick your poison. Staying at Waipio overnight is not allowed but under the circumstances I could see bending the rules to tackle this in the cool morning. To "Tex's" and portugese fried donuts…
Gear-wise: No sleeping bag needed but will need some insulation as temps go down to the 60's with wetness. Less gear but the weight is more than made up by the amount of water needed, plus I brought some Gatorade "G2". I went "no cook" this time but there is a place in Kona that sells MSR isobutane canisters at the time of this writing. While "no cook" was easier, kind of missed having a warm dinner when the rain came in.
Food-wise: Plenty of major grocery stores plus a Starbucks and local Kona coffee houses as close as Waimea. Bring liquids.
Season-wise: This trip saw a lot of rain and compared to my last drier trip in June 2007, I prefer the lush green even with the accompanying drizzle and rain.
General-planning: When going over, it pays to stay awhile. So backpacking is just one of the activities after watching the trained manta rays or snorkeling or kayaking. If you hit the websites early enough, there are relatively cheap airfares. July is when the prices rise due to the rush of tourists trying to make it for their summer break.
