1985 Map of Mopah Peaks

About this map

The Turtle Mountains dominate this high-desert landscape in eastern San Bernardino County, where dramatic volcanic topography meets the alluvial plains. This 1985 provisional study captures the area's geological complexity, centered on the distinctive Mopah Peaks and the prominent Castle Rock landmark to the south. The presence of Mopah Spring provides a rare point of historical water access in an otherwise arid environment characterized by extensive drainage systems like Gary Wash. The transition from the high peaks into the broad Vidal Valley reveals a classic Basin and Range terrain pattern, with the mountain front dropping sharply to the valley floor. Researchers and geologists can trace the intricate contouring of the range, which serves as a vital record of this protected wilderness area's natural state before late-twentieth-century shifts in land management.