Powell grew up in Kansas but studied art in Chicago where he also did commercial work for companies such as Wurlitzer. In 1927, Powell and his wife moved to San Francisco, where he set up a studio until the stock market crash of 1929. Out of work as an artist, he went to work for the WPA, first as a flagman on a road crew. But when his creative talents came to light, Powell was transferred to the National Park Service. Powell is believed to be the primary artist for the Yosemite, Yellowstone, and Zion serigraphs.
The poster project was closed down in 1941, with the onset of Word War II. When his assignment for NPS ended, Powell took a course in marine drafting and went to work as a modeler at Kaiser Shipyards in nearby Richmond, California. After World War II, Powell taught Adult Education courses in silk screening for Oakland City Schools and continued to pick up freelance jobs. His post-war work was mostly architectural — designing churches, schools, gymnasia, and houses — although he also did sign making, magazine and book illustration, set design, painting restoration, and commercial artwork. The last nine years of his life were spent as a draftsman with the 6th Army Engineers. He died virtually penniless and is buried in Hayward, California.