Complex sentence: According to the USGS, variant names of Catoctin Mountain include Kittochiny Mountains, Kittockton Mountain, South Mountain, and Kittocton Mountain, however in Maryland, South Mountain and Catoctin Mountain are separate, roughly parallel, mountains.
Split into simpler sentences: According to the USGS, variant names of Catoctin Mountain include Kittochiny Mountains, Kittockton Mountain, Kittocton Mountain, and South Mountain. However, in Maryland, South Mountain and Catoctin Mountain are separate, roughly parallel, mountains.