Swinnerton was born in Southern California. He gained his artistic training at the San Francisco Art Association Art School, and became a pupil of the great William Keith. He began his career as an illustrator and moved to New York City. After becoming ill with tuberculosis, he return west.

During this time, he began to explore unfamiliar regions of deserts of New Mexico, Arizona, and Utah. It was here where he first became entranced by the beauty of the desert. Like many artists, the sweeping and mysterious qualities of a dry wasteland became alluring to the young artist. Soon, the magnificence of monumental desert bluffs, dramatic shadows, and sweeping desert skies became the primary subject matter of his painting. Swinnerton’s early paintings were highly realist, detailed depictions of an endless landscape. His subjects often focused on the exotic contradictions of the desert, a place where the parched land coexisted with thriving beauty.  Many of Swinnerton’s later paintings took on more minimalist qualities with a monochromatic palette of earthen tones.  Often consisting of a single tree, or unadorned sand and brush, he captured the lonely, arid landscape and in all it’s splendor.