During the Jurassic Period, Utah was located between 20 and 30 degrees latitude, significantly further south than today. The majority of the Entrada Sandstone represents a vast sand sea, or “erg”, a desert eolian system similar to the modern Sahara Desert. Our study area focuses on a sediment starved region between the erg and coarse-grained alluvial fans draining the Elko Fold Belt. We focus on Entrada outcrops extensively exposed along the eastern side of the San Rafael Swell, a Laramide monocline. Historically dismissed and vaguely defined as “earthy” redbeds, here the Entrada displays a much finer grain size with high mud content and a nearly complete absence of eolian dune facies.