The Hair-Trigger Kid by Max Brand

In the sunset of that day, the black mare and the silver stallion stood on the crest of a hill overlooking the big hollow through which Hurry Creek ran from ravine to ravine. The light was growing dim, but still there was enough of it for the Kid and Bud Trainor to see quite clearly.

There was a continual shifting and flowing, as it seemed, of the very ground that led down toward the water. It was the troubled maneuvering of masses upon masses of thirsty cattle. Still, from the outer reaches of the ranch, the cattle were drifting in toward the familiar watering place. They could be seen coming, sometimes singly, sometimes in patient files that went one behind the other, winding across the well-worn trails. From the hills on top of which they had a view of the creek, these approaching animals were sure to send out a deep lowing as they were made aware of a new and unprecedented condition there by the water which was life to them.