After leaving Madison, Richardson took graduate course work at Harvard in chemistry and mineralogy, followed by accepting appointment at Olivet College in Olivet, Michigan where he briefly was a professor of mathematics and physics. In 1891 he moved to Salt Lake City due to his interest in mining. He became involved with a number of mines in the Bingham Canyon mining district, notably the Old Jordan and South Galena mines. In 1895, he moved to Anaconda, Montana where with a Mr. Olson, Richardson together with his brother-in-law, Charles Francis Adams, ran a merchantile, supplying clothes and other dry goods to the miners. In 1899, he and his brother-in-law returned to Salt Lake City and opened the firm of Richardson & Adams. Richardson & Adams primarily ran an upscale clothing store (clothier) in downtown Salt Lake City, but it still also held a number of mining claims.