I bought the poster last summer, when my family visited the Grand Canyon. We backpacked down the Hermit's Rest trail all the way down to the Colorado River and slept under the stars.
Have you heard about the amazing names geologists have given the layers of rock in the Grand Canyon? Do you know where the layers of rock came from, and how the Grand Canyon was formed?
If you're curious, here's a place to start!
You can learn more about Grand Canyon geology from these books:
Grand Canyon, by Patrick Cone. Carolrhoda Books, 1994.
Grand Canyon, by Jan Mill. Macmillan, 1988.