I found this great documentary about the Dust Bowl. It fits in great right now as I am teaching about erosion. This is an example of how human impact combined with changing climate conditions significantly affected the Great Plains during the 1930s and opens the door for some engaging discussion about human impact on the land today.
Word of caution: 2 instances of language use that may be considered inappropriate for elementary students
I plan to fast forward past those spots. Make sure you preview completely before using in your classroom.