We are planning a 9 day trip from Kathmandu overland to Lhasa around the end of April, 2011. Is this route open for overland USA travelers at that time? From Lhasa we would like to take the train to Xian - spend a few days and take the train to Datong. Then travel on to Beijing for our return prebooked flight to USA. Can visas for both Lhasa and China be obtained in Kathmandu? Should train arrangements be made in Kathmandu or Lhasa?