River Trek is a strategy game of placing trading posts and moving stacks of explorers along the path of a river.
On your turn, you pick up a stack of explorers, called a caravan, and move it mancala-style by dropping the explorers one at a time off the bottom of the stack as it travels forward. Each explorer dropped on a space earns money if a trading post of the same color is on the space, so other players may earn money on your move. Drop an explorer on a river crossing, and it washes downstream to the previous river crossing. Drop an explorer on an animal token, and the owner of that explorer receives a special ability.
When a caravan reaches the source of the river, the game ends and the player who has made the most money along the way wins.
—description from the publisher