Tavallaan osa tapahtumista seurasi aika tarkastikin alkuperäistä tarinaa. Koko intiaanipoika-hommeli on tietysti fiktiivinen ja lopullinen kostoretki ei mennyt samalla tavalla kuin leffassa tämän takia. Alkuperäinen Glass jätti molemmat hänet hylänneet miehet henkiin jahka oli yhyttänyt heidät.
Near the forks of the Grand River, near present-day Shadehill Reservoir, Perkins County, South Dakota, while scouting for game for the expedition larder, Glass surprised and disturbed a grizzly bear with two cubs. The bear charged, picked him up, bit and lacerated his flesh, severely wounding him, and body slammed him to the ground. Glass managed to kill the bear with help from his trapping partners, Thomas Fitzpatrick and Jim Bridger, but was left badly mauled and unconscious. General Ashley, who was also with them, became convinced he would not survive his injuries.
Ashley asked for two volunteers to stay with Glass until he died, and then bury him. Young Jim Bridger, then 19 years old, and John S. Fitzgerald, then 23 years old, stepped forward, and as the rest of the party moved on, began digging his grave.[7][8] Later, claiming that they were interrupted by attacking Arikara Native Americans, the pair grabbed the rifle, knife, and other equipment belonging to Glass, and took flight. Bridger and Fitzgerald later caught up with the party and incorrectly reported to Ashley that Glass had died. There is a debate whether Bridger was one of the men who abandoned Glass.[9]
Despite his injuries, Glass regained consciousness, but found himself abandoned, without weapons or equipment. He had festering wounds, a broken leg, and deep cuts on his back that exposed his bare ribs. Glass lay mutilated and alone, more than 200 miles (320 km) from the nearest American settlement, at Fort Kiowa, on the Missouri River. Glass set the bone of his own leg, wrapped himself in the bear hide his companions had placed over him as a shroud, and began crawling back to Fort Kiowa. To prevent gangrene, Glass allowed maggots to eat the dead, infected flesh in his wounds.
Glass crawled overland south toward the Cheyenne River, using Thunder Butte as a navigational landmark, where he fashioned a crude raft and floated downstream to Fort Kiowa. The journey took him six weeks. He survived mostly on wild berries and roots. On one occasion, he was able to drive two wolves from a downed bison calf and feast on the raw meat. Glass was aided by friendly Native Americans who sewed a bear hide to his back to cover the exposed wounds and provided him with food and weapons.