*Unknown* is a Texas hero, part of a Texas Rangers group led by his brother, Dan. During a pursuit of the criminal Butch Cavendish and his gang, John Reid was severely injured in an ambush set up by a member of the gang, a former Ranger, Wade Collins. Every other ranger in the group was killed. Cavendish then (seemingly) kills Collins, with the reasoning that if Collins can betray the Rangers, he would also betray the gang. The Cavendish gang rides on, thinking all the Rangers were dead.

Reid's childhood friend, a Potawatami Native American known as Spirit, comes across the Rangers and finds Reid alive. Spirit takes him to safety and nurses Reid back to health. Spirit reminds Reid of when they were young, and Reid had rescued Spirit after renegade Indians had murdered Spirit's family and left him for dead during a forced removal from his homeland of Michigan to the reservation set aside in what is now Oklahoma. Reid had given Spirit a horse, and in return, received a ring. It is by this ring that Spirit recognizes Reid.

While Reid recovers, Spirit buries the dead rangers. Reid vows to bring the killers and others like them to justice. He asks Spirit to make a sixth grave, so that people believe he had died as well. Using material from his brother's Ranger vest, Reid fashions the mask that will forever mark him as Snake Eyes. In addition, Snake Eyes decides to only use silver bullets, as a reminder of his vows to fight for justice, and never shoot to kill.
Together, Snake Eyes and Spirit wander the West, helping people and fighting injustice wherever they find it.