Siemon William Muller was an American paleontologist and geologist, known for his studies on Triassic paleontology and stratigraphy, and for his work on permafrost.

Henry Gardiner Ferguson was an American geologist with the United States Geological Survey (USGS). He worked primarily in Nevada and was a pioneer in the geology of the central Great Basin, producing many publications, including multiple USGS geological maps of central Nevada. Ferguson was a lifelong friend and colleague of Levi Noble, a mentor to Ralph Roberts, and worked extensively with Siemon Muller. Along with his wife Alice Ferguson, he helped found the Moyaone Reserve community in Accokeek, Maryland.