1:05:20

History of Forests in Illinois Webinar Presentation

28:42

Folding Rocks; From the Miniscule to Giant Mountains

1:02:23

Overview of Indiana Geology

58:27

Rarest Trees of Illinois Webinar

8:02

Yellowstone's fantastic basalt columns and underlying stream gravels at Tower Fall

1:52:01

Origin and Evolution of the Western Snake River Plain

26:15

Every Layer of the Grand Canyon, Explained

1:15:53

Seminar 24: State of the Pacific Ocean off Canada and the U.S.