The McRae Group is a thick sequence of Late Cretaceous rock in southern New Mexico, especially around Elephant Butte Reservoir, the Caballo Mountains, and beneath much of the Jornada del Muerto. Composed of the Jose Creek, Hall Lake, and Double Canyon formations, it preserves more than 3,000 feet of conglomerate, shale, siltstone, and sandstone deposited in varied environments, including humid alluvial fans. Its plant and vertebrate fossils, including ceratopsians, ankylosaurs, sauropods, turtles, Alamosaurus, Triceratops, Sierraceratops turneri, and Tyrannosaurus mcraeensis, make it one of New Mexico’s key dinosaur-bearing rock units. First named in 1952 and later reclassified, it remains central to ongoing geological and paleontological study.