Complex sentence: The desert's high elevation and location between mountain ranges influences regional climate: the desert formed by the rain shadow of the Sierra Nevada that blocks moisture from the Pacific Ocean, while the Rocky Mountains create a barrier effect that restricts moisture from the Gulf of Mexico.
Split into simpler sentences: The desert's high elevation and location between mountain ranges influences regional climate. The Sierra Nevada produces a rain shadow effect that blocks moisture from the Pacific Ocean, whereas the Rocky Mountains create a barrier effect that restricts moisture from the Gulf of Mexico.