Chang Yiap trail in Kaeng Krachan

To my knowledge this trail (I think it is actually km17) is one-way. Though in the first few hundred meters there is a trail branching off to the right which comes out on the road (as long as you don't get lost on the various side trails). I don't know exactly how far it goes, but for as far as I have followed it it kept following the stream bed, so at least getting lost is not a major risk.

I guess the best option is to ask a ranger at Ban Krang to join you.
Enjoy!

I will ask at the weekend. In my own meanderings in the area I have only seen animal tracks beyond the waterhole. There was a camp ( a logging camp I thought but again I will ask) but at the beginning the trail - about 200 meters from the road. You can still see the old camp track (its more of an old road) that takes you through to the 3rd stream crossing - walk in 200 meters then take the left fork over the fallen tree. Elephants still use this old track which is cut into the hillside.

You are right Geoff, the track you refer to continues (continued?) until it meets the old logging road (the one that comes out at kilometre 11 and has a red/white barrier). Theres an old camp about 7 km in. Nobodies aware of the last time anyone used it so we went and had a look (with the assistance of a ranger who had walked the trail in the past) - we lost the trail 50 meters beyond the birder's water hole and just found criss crossing animal tracks.

Interesting information, thanks for sharing Trekker!

It's a bit of a shame the rangers are letting these trails disappear. Earlier this year I did an attempt to walk the trail to the 'real' Panoen Thung Mountain (the highest point of the park, 1200m asl if I am correctly informed.).
Even though I could see where the trail was heading, the bamboo had obstructed the way so much that it was more crawling than walking.
After a while I gave up...

Maybe instead of a cleaning day, we should organize trail maintenance days, haha.