In 1986 I went to The mouth of the Melinau Gorge, which I believe is Camp 5? and camped there alone for about five days. Please understand, it has been many years and I don't have a map in front of me!
One day during a flood I observed that the waters of the Melinau were suddenly turning left and running backwards at a point shortly before it enters the main river, so I explored up the gorge on the right on the flank of Gunong Api. I don't clearly remember the sink point, but it was obviously an overflow of some sort for floodwaters and there was no way in, nevertheless there must be a cave there. Are there not passages in Clearwater and others that parallel the face of Api? And perhaps have a lower level that accepts floodwater? After all, the valley surface is entirely composed of alluvium, and there could even be flooded passage in the alluvium covered bedrock?
The next day I was about 1/4 mile or so up the gorge and climbing up the huge scree blocks of Api when I felt cool air issuing from the scree, then found a horizontal crack that I was able to follow back for about 100 feet. The air was not particularly strong and I was still in breakdown. I was alone, and only had one pitiful light, so I turned back. Wouldn't that be near Whiterock Cave?
I am sure someone must have checked out a lead so close to camp, but don't know. Do you?
I'm sorry to say that I have never been back!
After Mulu I went up the Baram, then up the Sungai Akah past Long Tebangan which is the last longhouse to a bizarre plateau composed of oil shale and covered entirely with Rhododendrons and carnivorous plants such as Nepenthes. The water was blood red and had a pH of about 3. According to the Locals no one had ever been there before, they were completely unaware of what was on top. From there I continued upstream to the Sungai Kitan, then climbed the mountain to discover a cave on the very top filled with billions of bats of many different species. There was no other karst anywhere nearby, just one chunk of limestone on the very top of the mountain.
It was all such an excellent adventure that when we returned to Long Tebangan the chief embraced his son in tears and said "You are now a man and will be the next Chief!"
AKA: Bruce J. Morgan
Archer, FL 32618 USA
352 495 9748