A critical factor required to unravel processes that have shaped other planets is a solid understanding of geologic processes as they operate on Earth, and a logical way to understand those processes is to go into the field and view them. We provide a field guide to three locations: (1) Cima volcanic field, south of Baker, California; (2) Rainbow Basin, north of Barstow, California; and (3) Red Rock Canyon and vicinity in Nevada and California, all within the Mojave Desert of the southwestern United States. These locations highlight three processes that have affected Earth and other planets: volcanism, sedimentation, and tectonism. Volcanism is explored by looking at the basaltic cinder cones, lava flows, lava tube, and xenoliths of the later Tertiary and Quaternary Cima volcanic field. Felsic ash and volcaniclastic material interbedded with lacustrine, siliciclastic sedimentary rocks are examined in Rainbow Basin, a Tertiary strike-slip basin. The interplay between volcanic and sedimentary processes is examined at this locality, while deformation of the basin makes it ideal for examining structural and tectonic aspects. Broader-scale tectonism is observed in the hanging wall (Ordovician carbonates) and footwall (Jurassic sandstone) rocks to the Keystone thrust fault. The fault is visible given the color contrast between the lower (white and red) and upper (gray) plates. In Red Rock Canyon, Nevada, exposures of the Jurassic Aztec Sandstone display excellent examples of large-scale cross-stratification from eolian dune deposition. Each locale holds lessons pertinent for the study of processes that have operated on other planets in the solar system.