The trailcams snapped about 4,000 photos between mid April and the end of May, which is when you see more of the Virginia Range mustangs at the higher elevations.
This scene is typical: They come in, drink and are gone in two minutes.
The situation might be different if the water source was a spring, as the vegetation might be more appealing.
Western Horse Watchers Association 
Our Nevada/Utah wildlife cams show the same movement whether the water source is a spring or pond. Seldom is there grazing in the immediate area as the bands of all wildlife move in, drink, and move on.