When Oscar Fitzallen McCombs was born on 27 June 1857, in Yountville, Napa, California, United States, his father, Benjamin Franklin McCombs, was 28 and his mother, Nancy Lavina Lear, was 18. He married Cora Belle Steele on 8 June 1890, in Blaine, Whatcom, Washington, United States. They were the parents of at least 2 sons and 1 daughter. He lived in Tenmile, Whatcom, Washington, United States in 1900 and Bellingham, Whatcom, Washington, United States in 1910. He died on 9 June 1939, in Ketchikan, Ketchikan Gateway Borough, Alaska, United States, at the age of 81, and was buried in Ketchikan, Ketchikan Gateway Borough, Alaska, United States.