McDonald Observatory

William Johnson McDonald was a banker in Paris, Texas, who died in 1926 and left most of his fortune to the University of Texas to build and equip an astronomical observatory. The university chose the Davis Mountains, high and dry and far from city lights, and the first telescope was dedicated in 1939. The observatory remains a research unit of the University of Texas at Austin and enjoys some of the darkest night skies in the continental United States.

The domes stand on the summits above TX-118, northwest of Fort Davis. The 82-inch Otto Struve Telescope was the first, and the larger Harlan J. Smith Telescope came later. Astronomers here map millions of galaxies to study dark energy, look for planets around other stars, and use white dwarf stars to work out the age of the Milky Way. The observatory is also a founding partner in the Giant Magellan Telescope under construction in Chile, and it produces StarDate, a two-minute radio program heard on about 350 stations.

Visitors check in at the Frank N. Bash Visitors Center, open Tuesday through Saturday from noon to 5 p.m. It has astronomy exhibits, solar viewing through a dedicated telescope, and tours of the big telescopes. Star parties are held three nights a week, with constellation tours and viewing through telescopes, and they often sell out at spring break and holidays, so buy tickets ahead. Residents of Jeff Davis, Brewster and Presidio counties get in free.