a look at films featuring the willamette river, the l.a. river, and the colorado. coming up, on "earth focus." in the united states, we have more than 3.5 million miles of rivers. that's enough to circle the globe 140 times. rivers shape our landscapes, are home to many species, fill ou glass, and even inspire filmmakers. >> if we're going to be a society that uses rivers, and lives along them, then we do need to live in a more river-conscious way. >> seeing kids get so excited about the river is, uh, probably the most gratifying experience that a filmmaker can have. >> they may start out pure, but pollution, urbanization, and agriculture have degraded rivers. in his upcoming film, "willamette futures," jeremy monroe looks at how everyone, from city-dweller to farmer, is connected in helping revitalize oregon's willamitte river. >> the water starts out some of the purest water on earth. crystal clear, cold. >> we have some of the best water quality coming out of the ground in the world. >> that's the type of water that we start with in our headwaters. >> the questi