Robert Roy Coats (1910–1995) was an American geologist known for his studies of the Aleutian Islands and his exhaustive report of Elko County, Nevada.

He continued graduate work at the University of California, Berkeley, receiving his doctorate in 1938, with a thesis on the ore bodies of the Virginia City mining district in Nevada.

He correctly interpreted: Coats’s colleagues from the Alaska Branch of the USGS have commented on his extraordinary ability to comprehend the detailed geologic history of an area with only the most cursory examination.

In 1954, he began a long and productive period of work in Elko County, Nevada, where he studied rhyolites, stratigraphy and structure, and mapped the geology of the Jarbidge, Owyhee, Mountain City and Tuscarora 15’ quadrangles.

Many of his 70 publications were based on his work in this period, which culminated in his 1987 synthesis report on the Geology of Elko County, a complex area the size of Connecticut and Massachusetts together.