Possible Clues:

• Soldier died in the wilderness
• Good chunk of Mongolia
• Mongolian dry spot
• Desert along the Silk Road
• Mongolian "place without water"
• It's Mongolian for 'waterless place'
• The Green Wall of China is designed to slow its expansion
• Digs up lead from inland marsh in desert
• 'Call of Duty: Black Ops II' desert setting
• Large desert plateau of southern Mongolia and northern China