Waterlots
An old bull, whipped by a society of younger, stronger bulls, may choose to remain longer in his summer querencia than is safe for him. He might stay after all the other cattle have gone, eyen though frost is covering him each morning, all the feed is gone, and his watering place is drying up.
Water holes are often fenced for the purpose of controlling the cattle watering there. These fenced areas are called waterlots. If an outfit wants to gather an area it shuts the gates to the waterlots and the cattle are held there by their desire to drink until the cowboys come to gather them.