No mountain system in the world has a greater influence on weather than the plateau of Tibet and its fringe, the Himalayas. Even the tallest chains in the U.S., the Rocky Mountains, Brooks Range, Cascades and Sierra Nevada, can’t rival the control that the Tibetan plateau exercises over climatic conditions in Pakistan, India, China and the many smaller countries of southeastern Asia. Created 50 million years ago by the collision of the Indian and the Eurasian Plate, the Himalaya range is the highest, but also one of the youngest mountain chains.