but the waterway remains in danger due to climate and overuse. this river is iconic. reporter: this man spent much of his life on the colorado river. it is a remarkable area of the world. reporter: as an avid add ten adventurer and he made it his life mission to protect it. the colorado river powers city, waters farms and quenching the thrift of some 40 million people and a critical refuge for wildlife and it is under threat. there is more overuse. there is more water taken out of the river. if we continue to overextract the bank account, we re going to run dry. reporter: an usually wet and