He painted the adobe buildings of Spanish missions in California, Arizona and New Mexico, with a focus on colors and nocturnes.
[4] Upon his return to the United States, he pursued his artistic career in Denver, Colorado, and he subsequently settled in San Francisco, California.
[4] Sparks painted the bluffs of Santa Catalina Island and the landscape of Niles Canyon as well old windmills in Mexico.
[5] However, most of his work consisted of the adobe buildings of the Spanish missions in California, Arizona and New Mexico.
[8] Sparks was a co-founder of the Hotel Del Monte Art Gallery in Monterey, California in 1907.