The Shape of Water

A snowflake is sitting on some grass.

On January 28, 1887, the cavalry detachment guarding the banks of the Yellowstone River against the Great Sioux ­Nation was covered by an amazing snowfall. The weather had been warm, so one of the falling snowflakes quickly drew the ­attention of the General — at almost 15 inches in size, it is still thought to be the largest snowflake ever seen by humankind.