Streams and rivers flowing through the mountains created V-shaped valleys that would later be deepened and widened by glaciers.
(rivers; flowing; through the mountains) (Streams and rivers; created; V-shaped valleys that would later be deepened and widened by glaciers) (V-shaped valleys; would be deepened; T:later) (V-shaped valleys; widened; by glaciers)
rivers Streams and rivers V-shaped valleys V-shaped valleys
flowing created would be deepened widened
through the mountains
V-shaped valleys that would later be deepened and widened by glaciers
T:later
by glaciers