During both his trips to the western United States, in 1859 and 1863, Bierstadt observed and sketched the American buffalo (actually bison) that dominated the rolling grasslands from the Mississippi River to the Rocky Mountains. In The Buffalo Trail, made after his second trip in 1863, Bierstadt depicts the seasonal migration of the buffalo between feeding grounds and salt licks.
At this time, the creatures were beginning to be threatened by extinction from excessive hunting. Hundreds of thousands of hides were being shipped back east by the 1870s, and by 1880 only a few thousand buffalo remained. Bierstadt himself had hunted them on his first trip West, but, as Ludlow writes, on the 1863 venture he focused solely on sketching: “Our artist [Bierstadt], though a good shot … had seen enough buffalo-hunting in other expeditions to care little for it now, compared with the artistic opportunities which our battue [hunt] afforded him for portraits of fine old bulls.” In this painting, rather than feature a solitary animal, Bierstadt instead silhouetted a whole herd against bright reflections in the stream, as sunlight breaks through ominous clouds.