Thank you for writing this incredible description of your trip!

You mentioned that of the people who visit on foot about half take the Motu/Otipi Rd and the other half go up the Mangakirikiri/Mangamate. Do you remember any factors that made you take the Mangakirikiri/Mangamate route?

This track is now cleared and well marked all the way from the road to the hut and all wind fall has been cleared, a ladder has been installed at the rock face exiting the last creek before the bridge, this work was completed on the 21st March 2019 by Permolat members and the Over Forties Tramping Club, refer to the remote Huts site for confirmation, I organised the work. The walking times now would be 5 to 7 hours, unless you were running it could not be done in 3.5 hours with rests stops as stated above.

This route should not be taken lightly. All pretty straight forward until the Pine Creek sidle. This was beyond what our group felt comfortable with as the consequence for falling / slipping is extremely high. We ended up dropping down the SW side of the ridge between peaks 2000m and 2082m which resulted in us being bluffed out 200m from the lakes edge. 3 fit, capable and young trampers found themselves well out of there depths. In hind sight I believe the Pine Creek sidle is the only feasible route but its some proper scary shit. Those who have been before us were brave, those that go after us good luck . Note didn't see any cairns, plenty of water on the tops.

As noted the Vane Stream can be difficult to cross. I was in a party of two travelling down The Evans from the Bracken Snowfield to Smyth Hut about 5pm on a fine summers day in January. Vane Stream was high from snowmelt, we searched a few hundred metres up it but couldn't find a place to cross. We camped at the forks overnight and crossed early in the morning when the snowmelt had eased off, still challenging but we got across safely enough using mutual support.

I strongly advise looking at the photo that @gibbler links to below. The route guide in Moirs is very confusing ('climb the last fan before the waterfall to the base of cliffs') as most parties I speak to climb the next fan upstream from the one indicated in the photo leading themselves into steep, dangerous country if they try to follow the Moirs instructions from there. Moirs presumably means the second-last fan, as indicated in the picture.

Either the route indicated in the photo or that described by Yarmoss here are good, safe options.

Yes following the stream beds (which very dry went I went) is the easy way to travel.
That "upper" bit of track through the trees is unmarked on the topo map.
There was blaze tape in a tree on the true-left bank to indicate when to leave the stream bed and to look for the marker in the scrub - that indicates the start of the track through the lower portion of bush. The topo map incorrectly leaves out the double ford of Mistake Creek near the bottom - it shows a single ford. And the orange marker at the other side of the first ford was hard to see (actually it was easier to ford more downstream anyway).

There is a picture of the true-left waterfall route at:

http://www.southernalpsphotography.com/Tramping/Fiordland/Triton-Peak-U-Pass

I found the waterfall bypass quite easy (it was very dry at the time though). There are good footholds and things to grab while climbing the "natural staircase" and once past the lower bluffs it isn't too steep.

I suggest grabbing water as you pass the waterfall at the top because there wasn't anything easy to get on the (camping) flat.

Hut now in good condition thanks to the work of the Whakatane tramping club. The lower sleeping bench needs repair

Start of the track,coming from Otane, to Otapukawa hut is now marked with a large orange marker on a log. The stream itself is very narrow and overhung with ongaonga.
About 5m into the bush is an old handwritten track sign. The stream is narrow and "gutter" like. Just before the ascent to the saddle the creek divided, take the left branch and about 20m in is a marker. Once on crest go east 50m before descending.The initial section of track down the Wehiwehi stream is in the bush and in places poorly marked with windfall.

A small waterfall 500m down stream from the hut can be passed on either side. TR probably easier

Good condition although hard to find. 4 wheel drive track stops at base of small cliff. Track to hut starts here (yellow marker). Walk close to base of cliff and you'll find the track start

Hut was in good condition thanks to a party who had visited and cleaned up a month earlier. Hut book suggests visitors about once/month.
Door catch broken, held closed with a spade

Track well marked but 2 areas of significant windfall on the descent into Tawawharara stream. Keep to the spur

The track start is now obvious,immediately opposite the sign pointing to Te Panaa Hut.
Route well marked but overgrown.Numerous trap lines (yellow markers) from crest, be sure to descend the right ridge

AKA 'Tree Nettle'. I brushed against some of this in the Port Hills above Christchurch. Googled it after the tingling persisted for three days. It's certainly pretty potent. Can't help wondering what evolutionary purpose the poison has. To keep the Moa off?

My first time on the saddle a couple of years ago I couldn't see a way down either. I didn't realise at the time how big and rolling the Kay Creek/Scott Creek saddle is. I haven't been down the actual route, but I photographed it from the bottom when down at Kay Creek for this trip. It looks very steep and you'd want to be careful in the wet as it seems to be all snow grass. This eastern route down through the bluffs is surprisingly easy. It had snowed the night before and all the rocks above were slick with melting snow (you can see the snow on the tops in this photo), so I cancelled my planned sidle to Sleepy Hollow. The snow grass here was perfectly fine for the descent. It's just not the most direct way down into Kay Creek if you're coming from the saddle!

So Moirs was right ... I came to the conclusion they;d stuffed up their right & left. Coulda sworn there was no way down the true right of that waterfall. Ended up following deer trails down the true left, which was ok, but a little exposed. Wouldn't want to fall.

Good story, thanks for writing it.

The sandflies dashing themselves on the tent reminded me of camping in the Beansburn on the Five Passes tramp - on sunrise, I really did think it was raining, so desperate was that blood-thirsty miasma.

For the newbie to onga-onga, contacting this stuff is painful. People are affected differently but contact will cause extreme pain.

On a tramp, a mate slipped and pressed his palm into one leaf - instant intense pain diminishing, after 2 hours, to a level that could not be ignored - lasting for 2 days.

Four days later, he had a delayed reaction - paralysis of the whole arm, blurred vision and associated pain for about 15 minutes - scared the willies out of him.

A sufficient dose of the onga-onga neuro-toxin can kill - so, BE CAREFUL.

From Cow Creek Saddle the track descends slightly and then sidles in the bush until it opens up at the head of an old and massive slip area. An easy scramble down into the eroded gully and follow the easy open stream-bed down the whole length of this open, and rather attractive area. Cairns and markers make the route easy.

Just before the bush is reached at the lower end, exit up onto the true-left bank and and pick up a marked entry back into the bush. Another 150m or so and Cleft Creek is reached. The map is not quite correct at this point.

Although not essential, it's easiest to cross Cleft Creek and proceed on the northern bank for a short while before re-crossing and picking up the orange markers at the start of the main track that follows easy and pleasant terraces to the Ruamahunga/Cleft Creek confluence. Not highly maintained, but the relatively stable old-growth forest won't claim it back in a hurry either.

This photo speaks to me of the promise starting a tramp. Easy walks up grassy flats with the peaks beginning to tower around you, flavoured by the anticipation of turning up one of those spurs...

A truely unique place. Well worth the climb.