It's done in a "found footage" faux-documentary style, which lately has been done to death, but in this case they make it work. The set-up is interesting -- a famous Crocodile Hunter-type TV personality mysteriously disappears and his family joins a film crew re-tracing his last voyage along the Amazon in the hope of finding him again. They come across his abandoned ship and discover some videos he left behind. They learn that some creepy stuff took place as supernatural forces start threatening them too.
The program has a little bit of everything, but presents it in an entertaining way, a little bit of Blair Witch Project here, a touch of The Exorcist there, and a whole lot of Lost atmosphere everywhere. It might sound derivative, but the production values are high quality and the performances hold it all together.
You might think that shooting it as a fake documentary ("mockumentary" is my term of choice) means that we'll end up with headache-inducing shaky camera syndrome and built-in excuses for low-budget effects, but the producers avoid all that by having the camera operators in the show be top-notch professionals using high-end equipment, including cool aerial cameras that allow the series to feature some breathtaking establishing shots. Cameras are in every nook and cranny, so there is no lack of different angles or points of view.
The scares are typical, but the cast does an admirable job of selling all that silliness to the audience. Bruce Greenwood is fantastic as the missing Dr. Emmett Cole, and he has plenty of screen time. Leslie Hope is solid as his driven wife Tess, and Joe Anderson has a bit of Sawyer in him as the troubled son Lincoln. Eloise Mumford is captivating as Lena Landry, the daughter of Dr. Cole's main cameraman who is also missing, and Paul Blackthorne delivers the goods as Clark Quietly, the shady producer with hidden secrets.
Right now, The River is all over the place, with paranormal storylines that deal with monsters, spirits, and magic. Although it might still be trying to find its footing, it has started off with some intriquing scenarios that have teased some possibly great things to come.