Dr. William Henry Gray, a physician and lay missionary for the American Board of Commissioners for Foreign Missions, was born on May 10, 1810. In 1836, he joined Marcus Whitman and Henry H. Spalding to travel overland and establish a mission to convert Indigenous people in what would become the Oregon Territory. In 1837, Gray traveled east in order to obtain more recruits for the missions. While in New York in the spring of 1838, he married Mary Augusta Dix; the couple would have eight children. That summer, the Grays traveled overland to the Pacific Northwest with missionaries Elkanah Walker and Cushing Eells. William H. Gray continued missionary work until 1842. In 1843, he was involved in the Wolf Meetings and meeting at Champoeg that established the Oregon Provisional Government; he subsequently served as a member of the Provisional Legislature.

From 1846 to 1855, Gray farmed on the Clatsop plains, and from 1855 to 1858 operated a sawmill. From 1858 to 1864, he lived in British Columbia, where he worked in the Fraser River mines and built a boat that he piloted along the Okanogan and Columbia Rivers to Celilo Falls. He subsequently lived in Astoria, Oregon, and wrote a history of Oregon that was published in 1870. He also served as secretary of the Pioneer and Historical Society of Oregon. Mary Augusta Dix Gray died in 1881; William H. Gray died in 1889. The couple were initially buried in Astoria, but in 1916 their bodies were reinterred at the site of the Whitman Mission near Walla Walla, Washington.