Percival Lowell Milan Observatory. In 1894 Lowell chose Flagstaff, Arizona Territory, as the home of his new observatory. At an altitude of over , with few cloudy nights, and far from city lights, Flagstaff was an excellent site for astronomical observations. This marked the first time an observatory had been deliberately located in a remote, elevated place for optimal seeing. For the next fifteen years he studied Mars extensively, and made intricate drawings of the surface markings as he perceived them. Lowell published his views in three books: "Mars" (1895), "Mars and Its Canals" (1906), and "Mars As the Abode of Life"
William Lowell Putnam become trustee. After Gus's death, William's second son, Roger, became trustee. In 1927, Elizabeth Lowell Putnam established the William Lowell Putnam Intercollegiate Memorial Fund in order to begin a college-level mathematics competition, the William Lowell Putnam Mathematical Competition. This contest, which continues to this day, began in 1935 under the direction of the Mathematical Association of America. Putnam's grandson by the same name, William Lowell Putnam, born 1924, was a geologist, businessman, and climber, and served as the sole trustee of Lowell observatory from 1987-2013. William Lowell Putnam William Lowell Putnam II (November 22, 1861 – June 1923) (more commonly