Here is mute testimony that large glaciers moved down the slopes of Mount Mazama, carving and gouging material from the sides of the valley.
(Here; is; mute testimony that large glaciers moved down the slopes of Mount Mazama) (large glaciers; moved; down; the slopes of Mount Mazama)
Here large glaciers
is moved
mute testimony that large glaciers moved down the slopes of Mount Mazama
down the slopes of Mount Mazama