The principal rivers of Asia have their sources on the Tibetan High Plateau and crisscross the area. During the summer months when snow is melting and heavy rain falls, these rivers become raging torrents which isolates the nomadic population. A few bridges were built in the 1960s but most have long since collapsed. The only means of negotiating these rivers in the summer is via a single steel cable which is dangerous to say the least. Jinpa has built 3 bridges in the past 2 years but many more are needed in order to open up these remote areas.