sentences:  The Andes, to the desert's west, are the primary reason for the Patagonian desert status as they inhibit the westerly flow of moisture from the southern Pacific from reaching inland.This creates a rain shadow that accounts for the formation of the desert and is why, despite approximately half of the desert being only about 200 miles from the ocean, such a large desert is found in the region.The cold Falkland Current off the Atlantic coast of South America also contributes to the area's aridity.