According to his church files, Thomas Umaok was born circa 1886 and was arbitrarily given the birthdate of April 8th. As a boy, Umaok was one of the early pupils at the Herschel Island day school.

In 1905, he married Susie Atagoak "native fashion". They were remarried under church auspices at Herschel Island, August 15th, after he and his wife had been baptized that same morning. Three years later Thomas and Susie were confirmed by Bishop Stringer at Fort McPherson.

Both Thomas and Susie attended the Hay River residential school for a few years circa 1915. During this period, Thomas' letters to Bishop Stringer showed greatly increased fluency in the writing and expression of his second language.

Although Thomas and Susie fished, hunted and trapped around the countryside, Thomas made an effort when at Herschel Island to hold church services and later, school.

Thomas Umaok and Bishop Stringer seemed to have enjoyed a close relationship, and it must have been a moment of great gratification to both men when Stringer ordained Umaok as the first Inuvialuit deacon during a ceremony at Herschel Island on July 30th, 1927.