This paper presents an overview of the prehistoric archaeological record of the Mojave Desert. The Mojave has the deepest prehistoric archaeological record in the United States, extending back to more than 200,000 years ago. Archaeology is the study of artifacts and features of past cultures in a variety of contexts. It will be useful to begin this overview in a temporal context.

Together the Pleistocene and the Holocene form the Quaternary period of geologic time. The Pleistocene was a time characterized by alternating periods of rapid and dramatic climatic changes. In North America, cool and moist periods north of about 40 degrees latitude saw cold glacial periods alternating with warmer and drier interglacials. Continental glaciation, with huge ice sheets up to two miles thick, did not occur south of about 40 degrees latitude. The Pleistocene started 2,588,000 years ago and ended 11,700 years ago. It was followed by the Holocene, a time of warmer and drier climates, which continues to the present day.

Drilled marine cores often have foraminifera. Because their shells record isotopes of oxygen and carbon they can be analyzed for records of the past composition and temperature of ancient waters. Oxygen-16 is slightly lighter than oxygen-18 (it has two fewer neutrons); it is more readily evaporated fromthe ocean’s surface. After moving over land as water and falling as rain and snow during cold times, oxygen-16 gets enhanced in glacial ice and comparatively depleted in sea water. The changing ratios of the two isotopes of oxygen can be used as a record of the onset and duration of cold moist glacial periods and the drier interglacial periods. This is the essence of the technique for assessing Marine Oxygen Isotope Stage (MIS) numbers. The current geologic period, the comparative warm and dry Holocene, is assigned MIS 1. Working back through time, cold wet glacial periods are assignedDrilled marine cores often have foraminifera. Because their shells record isotopes of oxygen and carbon they can be analyzed for records of the past composition and temperature of ancient waters. Oxygen-16 is slightly lighter than oxygen-18 (it has two fewer neutrons); it is more readily evaporated from the ocean’s surface. After moving over land as water and falling as rain and snow during cold times, oxygen-16 gets enhanced in glacial ice and comparatively depleted in sea water. The changing ratios of the two isotopes of oxygen can be used as a record of the onset and duration of cold moist glacial periods and the drier interglacial periods. This is the essence of the technique for assessing Marine Oxygen Isotope Stage (MIS) numbers. The current geologic period, the comparative warm and dry Holocene, is assigned MIS 1. Working back through time, cold wet glacial periods are assignedeven numbers. The Holocene (MIS 1) began approximately 11,700 years ago. It followed the last glacial period named the Wisconsin glaciation (MIS 2).

Although MIS 2 continental glacial ice did not extend as far south as California, mountain glaciers were present in the Sierra Nevada and the Transverse Ranges. The lowlands experienced times of increased rainfall, known as pluvials. More than one hundred pluvial lakes were in the Great Basin. Pluvials and interpluvials were not necessarily in step with glacial and interglacial periods.