From 1888 to 1916, he produced over 9,000 images documenting urban, rural, and Native American life in the Columbia Basin, and particularly Umatilla County, Oregon.
[2] Unlike most amateur photographers of the period, Moorhouse worked with and mastered the cumbersome and exacting equipment of professionals, including gelatin dry glass plate negatives, large cameras, and a tripod.
He, like other photographers of the time, depicted a romantic view of their subjects, staging shots to reflect their personal viewpoints and, in doing so, alter details and create inaccurate images[citation needed].
Records indicate that Moorhouse supplied his subjects, from an extensive collection of Native American artifacts, with the clothing they wore and the implements they held.
There are also thousands of images of small town and community life; businesses, schools, churches, and various forms of transportation, such as locomotives and automobiles.