His skills were noticed by a young William Randolph Hearst who brought Swinnerton to New York to work for his newspaper syndicate. He penned two comic strips, "Little Jimmy," and "Little Tiger." But, in 1903 at age twenty-eight, he contracted tuberculosis, and for health reasons relocated to California, this time to the desert community of Colton.

From 1903 onward, he was a painter of the desert. At first, his renditions were not accepted. Critics expected the vast wastelands of the Sahara, but Swinnerton persisted. He explored the Southwest throughout New Mexico, Arizona (nine years before it became the 48th state), Utah, and California. His favored subjects included the Grand Canyon and portraits of American Indians. He even had a comic strip of Indian children called "Canyon Kiddies" which was published in Good Housekeeping Magazine.

Decades after Swinnerton drw "Little Jimmy" and the "Canyon Kiddies," these strips were made into animated cartoons. In 1936, "Little Jimmy" was a guest star in Max