Go to the broken building at the end of the covered bridge. Go inside and into the room with the broken walls that overlooks the dry riverbed.

Get onto the broken wall at the remains of the right window. While standing on that broken wall, turn right and jump higher up that same wall until you are as high as you can get.

Turn right so you are facing the upstairs broken floor (red-patterned floor) and jump to the left-most edge of the section that sticks out to where you are. You should jump right up there.

Have fun sniping the riverbed from one end of that room or the covered bridge from the other end.