Becca Palczynsky October 20, 2011 GFL, Middle, 2011, OAS, Environment, U.S.A. Colorado River Running Dry Becca Palczynsky October 20, 2011 GFL, Middle, 2011, OAS, Environment, U.S.A. Click on the image above to download the lesson Description: Students will learn how human environment interaction has caused the Colorado River to become an endangered river. Grade level(s): Middle Standards: GFL, OAS Produced By: Glenda Sullivan