In the Cultural Resource Overview for the Amargosa–Mojave Basin Planning Units (Warren et al., 1980), the study divides the region into four core planning units—each representing a major physiographic and cultural zone within the central Mojave Desert. These units form the backbone of what the Bureau of Land Management termed the Amargosa–Mojave Basin Planning Units, encompassing roughly 2.7 million acres between Death Valley and the Mojave River region.
Here’s the list with concise descriptions:
1. Bitterwater Planning Unit
Located along the southern margin of Death Valley National Monument, this unit includes the Silurian Valley, Salt Springs Hills, and parts of the Avawatz Mountains. It forms the northernmost segment of the Mojave Trough system and includes ancient playa remnants that preserve Lake Manly’s southern extensions.
2. Owlshead/Amargosa Planning Unit
Covers the Owlshead Mountains, Amargosa River Valley, and adjoining Funeral Range area. It bridges the Death Valley drainage to the north and the Mojave Basin to the south, containing key pluvial lake basins and rich archaeological deposits from the Lake Mojave and Pinto periods.
3. Kingston Planning Unit
Centered on the Kingston Range and Shadow Valley, this unit encompasses higher-elevation terrain with pinyon-juniper woodlands and evidence of upland seasonal use by prehistoric groups. It marks the ecological transition between the Mojave lowlands and the Great Basin uplands.
4. Mojave Basin Planning Unit
The largest and most southerly unit, it includes the Mojave River corridor, Cady and Soda Mountains, Broadwell and Soda Lakes, and the Cronese Basin. It serves as the principal connective trough between the Mojave River drainage and the Amargosa system, historically linking inland desert populations and later Euro-American travel routes.
Each of these planning units was chosen to represent a complete ecological cross-section—from valley floor to mountain rim—allowing researchers to analyze how prehistoric and historic populations adapted across environmental gradients. In your core project framework, these correspond to the hydrologic and cultural corridors that also define your Mojave River and Ancient Lake Systems project—linking Lake Mojave, Lake Manix, and the upper Amargosa–Death Valley chain through shared geology, hydrology, and cultural continuity.
Note: I am not a geologist, but a retired technician using AI to synthesize and connect information from established research and field studies. – Walter Feller