When someone spots an animal, road sign, or other item that is shown on the game boards, she points it out to the other players, who then mark the corresponding picture on their boards. (A horse on a billboard or in a trailer is as good as one in the field.) The first person to get five pictures in a row -- horizontally, vertically, or diagonally -- wins.
To make a set of reusable playing boards, cut the four quadrants from our page of bingo cards, and have them laminated at a copy shop. That way, boxes can be checked off with erasable markers and then wiped clean for another use. Alternatively, you can produce one-use boards by photocopying, cutting out, and marking with pen or pencil during play.