Yale Environment 360: Drought, mismanagement, and over-exploitation of its waters have made the Colorado River -- the lifeblood of the arid Southwest and drinking water source for 36 million people -- among the most vulnerable rivers in the U.S., according to the group American Rivers. In its annual report on Americas Most Endangered Rivers, the organization placed the 1,400-mile Colorado at the top of the list of threatened rivers, saying the iconic river is so dammed, diverted, and drained that it dries to a trickle...