Hugh Glass was born in about 1800. Little is known of his early life except that his family originally came from Ireland and that he was probably captured by Pawnee Indians when he was a young man.
On 13th February, 1822, William Ashley placed an advertisement in the Missouri Gazette and Public Adviser where he called for 100 enterprising men to "ascend the river Missouri" to take part in the fur collecting business. Those who agreed to join the party included Glass, Jim Beckwourth, Tom Fitzpatrick, David Jackson, William Sublette, James Bridger and Jedediah Smith.
Glass developed a reputation as a hard and courageous mountain man. He was wounded at Arickara but recovered and was one of those who survived Ashley's first expedition.
In August 1823, Glass was badly mauled by a bear. The leader of the party, Andrew Henry, left James Bridger and John Fitzgerald, behind to look after him. They became convinced he could not live and after taking his gun and equipment, abandoned him. When Bridger and Fitzgerald caught up with Henry they reported that Glass had died from his injuries.
However, Glass did regain consciousness and by eating wild berries and roots, he managed to crawl along the side of the Grand River. With the help of Native Americans Glass eventually reached Fort Kiowa. Glass now decided to track down and kill Bridger and Fitzgerald. Glass eventually found Bridger but decided to forgive him because of his age. He also discovered that Fitzgerald had joined the army and was no longer living in the region.
Glass now returned to life as a mountain man. Later he became a animal hunter providing food for people based at Fort Union.
Hugh Glass was killed by Native Americans while on the Yellowstone River in 1833.