This is the Rio Santa Cruz in southern Patagonia. It´s a massive glacial river that contains the only known run of Atlantic steelhead in the world. The other dude in the picture is pro snowboarder and steelhead guide Rodrigo Amadeo. As a matter of fact, he guided Krieger the past week and said Mel totally sucks at fishing. He got 1 fish in 7 days.
They came from a California strain of resident rainbow trout, not a true steelhead. They planted them in Lago Argentino about 100 years ago, and it is suspected that they evolved into Steelhead because the river system is quite poor in nutrients. People started fishing for them within the last 18 years, and the run seems to get better each year.