Complex sentence: The term "slide" likely refers to the large amount of eroded material along the base of the ridge, which ridge rises approximately 1000 ft (300 m) from the valley floor on the western side.
Split into simpler sentences: The term "slide" likely refers to the large amount of eroded material along the base of the ridge. The ridge rises approximately 1000 ft (300 m) from the valley floor on the western side.