While voluminous volcanic deposits were burying most of the Park's northern lands, a small volcano began erupting about 9.4 million years ago along the Tuolumne River about a mile upstream from Glen Aulin.
(voluminous volcanic deposits; were burying; most of the Park's northern lands) (a small volcano; began; T:about 9.4 million years ago; L:along the Tuolumne River; T:While voluminous volcanic deposits were burying most of the Park's northern lands) (a small volcano; erupting; )
voluminous volcanic deposits a small volcano a small volcano
were burying began erupting
most of the Park's northern lands
T:about 9.4 million years ago L:along the Tuolumne River T:While voluminous volcanic deposits were burying most of the Park's northern lands