They went on, continuing to watch, though there were no further signs of the men.
They had been on the trail twenty days when at dusk one day they moved slowly down a wide, gradual slope toward a desert.

At the foot of the slope was a water hole filled with a dark, brackish fluid, with a green scum fringing its edges.

The slope merged gently into the floor of the desert, like an ocean beach stretching out into the water, and for a distance out into the floor of the desert there was bunch grass, mesquite, and greasewood, where the cattle might find grazing for the night.

Beyond the stretch of grass spread the dead, gray dust, of the desert, desolate in the filmy, mystic haze that was slowly descending.
The cattle came down eagerly, for they had grazed little during the day in the mountainous region through which they had passed.

They were showing the effects of the drive.