Morda Coleman, later Morda Slauson, was introduced to William Polk Gray in 1923. Slauson was a journalist for the Walla Walla Union Bulletin and collecting pioneer stories for the Walla Walla Pioneer Pageant. Gray and Slauson corresponded regularly. Gray wrote to Slauson, daily sometimes. Slauson later became the publicity agent for the Walla Walla Chamber of Commerce, but she continued her friendship with Gray until his death in 1929.

William Polk Gray was born to William Henry and Mary Dix Gray in 1845 at Oregon City. He was the second of six children. Gray was introduced to sailing at an early age; at fifteen, he operated a mail boat out of Astoria, Oregon. At sixteen, he became Captain of a four-man crew primarily composed of Native Americans, which carried freight along the Frasier River. Gray led expeditions to Alaska during the Alaskan Gold rush, ferried supplies and troops during the Indian Wars, carried automobiles up and down the Columbia, and ferried cargo across the Snake River. Gray and his wife claimed land in Pasco, WA, where he became involved in city council and commerce. He founded the first Congregational Church in Pasco in collaboration with Luther and Clara Wilkins.

W. P. Gray and his wife built their home in Pasco, WA, and Gray was employed with the Northern Pacific Railroad as captain of the steamer "Frederick Billings". Three of the Gray daughters died from diphtheria during a two-day period. The Grays survived their other two children, Willeta and Hawthorne. Willeta passed away in 1922, and his last son, Hawthorne, died tragically in a successful attempt to earn the world record for high altitude in a free balloon in 1929. His writings reflect a deep sadness at the loss of his children.

William Polk Gray died on October 26 1929 at his home in Pasco, Washington.