The area on the dry, sheltered side of a mountain that receives very little rain is called a rain shadow.

Here's why:

* Orographic Lift: As moist air from the prevailing wind direction encounters a mountain, it is forced upward.

* Cooling and Condensation: As the air rises, it cools, causing water vapor to condense into clouds and eventually precipitation on the windward (wetter) side of the mountain.

* Dry Air Descent: The air that descends on the leeward (sheltered) side of the mountain is now dry and warm, creating a rain shadow area with very little precipitation.