31 Aug 2009 - A new exit was discovered by BC's Cave Survey Committee during their exploration of Nalsoc Cave's Branch1. The local guides, residents and leaders did not know of its existance and were surprised and pleased with the discovery. It would be considered a young cave because of the presence of intact and uncompressed coral fossils and a giant clam protruding from the breakdowns and walls. It has been named "Mel-let Cave" since Mel-let is the Ilokano equivalent to the Giant Clam (Tridacna gigas).
During this exploration a known exit, "Abot Aso" meaning "Dog Hole," was reached and GPS measurment shows it is 133 meters from the main entrance. Mel-let Cave is about 222 meters from the main entrance and is found in an obscure sinkhole. Between the two exits is a network of branches (always a choice of left or right branch every 50 meters or so) and a large chamber.
1-2 Aug 2009 - The survey of Nalsoc Cave's main passage was completed by the BC surveying team and Arthur C. Cebu, Sr. (MPDO, LGU-Bani) resulting with a survey total of 561.7 meters from the main to the sink hole entrances. Six branches and two loops were recorded for further exploration and survey, possibly in September.
26 July 2009 - Members of BC's surveying team and LGU-Bani performed an ocular inspection of Nalsoc Cave located in Brgy. Colayao to prepare for a cave survey that will be performed the following weekend. According to GPS readings the straight-line distance between the main entrance and the sinkhole entrance is about 425 meters. The initial inspection revealed numerous side rooms and possible branches.