Bison Bull in the Lamar River

A lone Bison Bull stands in Yellowstone's Lamar river just after sunset.  I have photographed from this vista many times over the years, but never made an image that I liked well enough to print.  On this June evening, I decided to photograph last light at this spot.  I composed a panoramic scene and the clouds turned a rosey color.  As I was exposing a few images I noticed something in the lower right of the frame.  A lone Bison was getting ready to cross the river.  The problem was that the river was deep enough that the Bison had to swim, and most of his body was submerged under water.  However, when he arrived at the other side, he stepped up into a shallow pool at the edge of the river and paused.  This gave me the perfect composition of his dark profile against the lighter water.  Click!  That momemt made the shot.