An Icy Stream                                          -      N      - 
(-------------------------------------------------)     W <---(M)---> E
                                                        -      S      -

As you travel deeper and deeper along the stream, the air becomes more
and more moist, as the air seems to become more humid.  There are no longer
small pieces of ice flowing about your feet, though the water is just as
cold.  The stream branches off in all different directions.