In truth, the Taur Virus dated back to 1867, which was 2 years after President Lincoln was killed, and people of the old west started shooting, while also gaining money. Cowboys were known as both heroes, and villains during those days, such as the notorious Billy The Kid, who liked to shoot anyone who was rich, and poor.
However, life in the west changed, when a new town on the map was discovered, and whoever went their on a horse would become fused with that horse, and remain there for the rest of their lives. Many people called this place "Hoof Hollow", based on how many people come out infected by the Taur Virus, which would cause a ton of trouble for anyone who would find this town. So, map creators have cut the location out of every map they have made, while keeping it a secret.