Possible Clues:

• Danger Hillary initially encountered in a 17?
• Great disturbance of fallen snow
• Sliding mass
• Ski area concern
• A clan have set out to cause danger in the mountains
• A new church established in a valley in the fall
• Landslide victory primarily secured by a male revolutionary
• Fall of molten rock flowing over in Italy too
• Keeping lava back can shift helium coming down the mountain
• Rapid movement of a large mass of snow or ice