Eastern New Mexico in the context of "North American monsoon"

New Mexico is a landlocked state in the Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also borders the state of Texas to the east and southeast, Oklahoma to the northeast, and shares an international border with the Mexican states of Chihuahua and Sonora to the south. New Mexico's largest city is Albuquerque, and its state capital is Santa Fe, the oldest state capital in the U.S.—founded in 1610 as the government seat of Nuevo México in New Spain—and the highest in elevation, at 6,998 feet (2,133 m).

New Mexico is the fifth-largest of the fifty states by area, but with just over 2.1 million residents, ranks 36th in population and 45th in population density. Its climate and geography are highly varied, ranging from forested mountains to sparse deserts; the northern and eastern regions exhibit a colder alpine climate, while the west and south are warmer and more arid. The Rio Grande and its fertile valley runs from north-to-south, creating a riparian biome through the center of the state that supports a bosque habitat and distinct Albuquerque Basin climate. One–third of New Mexico's land is federally owned, including many protected wilderness areas, 15 national parks and monuments, and three UNESCO World Heritage Sites wholly contained within the state—the most of any U.S. state.

The High Plains are a subregion of the Great Plains, mainly in the Western United States, but also partly in the Midwest states of Nebraska, Kansas, and South Dakota, generally encompassing the western part of the Great Plains before the region reaches the Rocky Mountains. The High Plains are located in eastern Montana, southeastern Wyoming, southwestern South Dakota, western Nebraska, eastern Colorado, western Kansas, eastern New Mexico, the Oklahoma Panhandle, and the Texas Panhandle. The southern region of the Western High Plains ecology region contains the geological formation known as Llano Estacado which can be seen from a short distance or on satellite maps. From east to west, the High Plains rise in elevation from around 1,500 to 6,000 ft (460 to 1,830 m).

The Dockum is a Late Triassic (approximately late Carnian through Rhaetian, or 223–200 Ma) geologic group found primarily on the Llano Estacado of western Texas and eastern New Mexico with minor exposures in southwestern Kansas, eastern Colorado, and Oklahoma panhandle. The Dockum reaches a maximum thickness of slightly over 650 m but is usually much thinner. The Dockum rests on an unconformity over the Anisian (242–234 Ma) aged Anton Chico Formation.

The Dockum and Chinle Formation were deposited roughly at the same time and share many of the same vertebrates and plant fossils. They appear to have very similar paleoenvironments. The two units are approximately separated by the Rio Grande in central New Mexico. This has led to controversy over the stratigraphic nomenclature for the Chinle and Dockum.