Preliminary Report

The Laos 2009 team is back from a very successful expedition to Oudomxay and Vieng Thong in Northern Laos. The most significant finding and major highlight since the expeditions started in 2002 is the exploration of the Chom Ong cave system 25km Northwest of Oudomxay town.

The system stretches along a 4km long mountain ridge and has a parallel running and interconnecting fossil and river passage. It was in just 5 days explored to a length of 11.3km with several wide open side passages remaining. It ranks now as the longest cave in Northern Laos and is one of the top 20 in all Laos. The typical passage dimension is 20-25m width and 20-30 m height. Two huge overlaying halls mark the connection of river and fossil passage with each 100m length, 30m width and ceiling heights of 30-50m.The cave is a trough cave and can be entered near the stream inlet and left at the outtflow. The full traverse takes 3.5 hours with additional 3 hours return walking time from Chom Ong village! The cave was pushed at the last day in a 15 hour trip to it current length.

The cave is currently developed as a cave for ecotourism. We received full support from the provincial tourism office in cooperation with Mr. Siegfried Moser from the German Development Service who covered all our expenses while staying in Chom Ong village. The director invited us during the farewell dinner to return again to Laos and promised an Oudomxay province cave entrance directory.

The visit of Vieng Thong yielded 3.7 further caving km with Kokai cave as most remarkable. The 20m wide and 1km long passage is covered over hundereds of meters with dry sinter basins and sinter pearls of 2-5cm diameter.

We are very happy to have explored the exceptional beautiful Chom Ong cave and enjoyed the great team atmosphere and cave talks during the evening. In total 15km of caves have been mapped during the 2 weeks. The project will return again to Oudomxay in January 2010.