Complex sentence: At its height during the last ice age, the lake may have been deep; prominent old shore lines, called strandlines by geologists, can be seen above Lee Vining and along volcanic hills northeast of the current lake.
Split into simpler sentences: At its height during the most recent ice age, the lake may have been deep. Prominent old shore lines, called strandlines by geologists, can be seen above Lee Vining and along volcanic hills northeast of the current lake.