Finally, rhyolite ash was deposited. Burro Mesa Pouroff showcases just one of many intriguing stories that lie in the Big Bend landscape. Continue down the Ross Maxwell Drive to discover more of Big Bend's spectacular geology. What we see today was not what ancient mammals, dinosaurs, and other creatures walking the earth saw millions of years ago. The earth's crust moves.
Seas come and go.
Wind and water erode and reshape the landscape. Some of these events, such as earthquakes, are dramatic while others, such as the building of a mountain range, take millions of years. As the earth changes, rocks record the events. The earth is always changing, no matter how quiet it may seem today. It is the nature of the earth to change.