A catastrophic landslide, one of the largest known on the surface of the Earth, took place within minutes in southwestern Utah more than 21 million years ago, reports a 91³Ô¹ÏÍø at Trumbull geologist in a paper published in the November issue of the journal Geology. The Markagunt gravity slide, the size of three Ohio counties, is one of the two largest known continental landslides (larger slides exist on the ocean floors). David Hacker, Ph.D., associate professor of geology at 91³Ô¹ÏÍø at Trumbull, and two colleagues discovered and mapped the scope of the Markagunt s...