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"
Goldendale Observatory State Park and north dome a diameter of 10 feet (3 m). The observatory served as the National Astronomical League's official headquarters during a solar eclipse which occurred on February 26, 1979, six years after the observatory opened. Approximately 15,000 people came to the town of Goldendale on that date to observe the eclipse. The Observatory and its lands were acquired by the state of Washington in 1980, after being operated by the Goldendale Observatory Corporation since its dedication on October 13, 1973. The park received its new designation as a "state park heritage site" in 2014. In July 2017, all structures