The terrain of the eastern Chorwon Valley is geologically complex, controlled by spatial relationships between Precambrian metamorphic rocks, Mesozoic granite, and locally intense structural deformations within and adjacent to major faults. Fundamental controls of terrain are overprinted by cycles of deep weathering and erosion during Pleistocene sea-level fluctuations, as well as by accelerated human impacts during the twentieth century. Geological characterization, terrain analysis, and Korean War history here provide significant lessons in the use of battlefield terrain.

Military access, mobility, and the orientation of attack corridors in this area are predominantly a function of major tectonic faults, and (to a lesser extent) lithology. Severely tectonized granite rock mass extends outward for 300 m to 2 km from major fault zones. Erosion of highly weathered granite in some of these zones forms elongate valleys. The easily-ripped saprolite by-products of granite weathering provide in situ construction materials (sand and gravel), soft foundations prone to boggy conditions in some areas, reasonable groundwater supplies near the fault zones, and an overall situation suitable for staging and military infrastructure. Resistant Precambrian metamorphic rocks form rugged terrain suitable for defensive positions. These hard lithologics support steep ridges and towering hills in and around the eastern Chorwon Valley in the Kumhwa vicinity. The (often) strongly magnetic character of some of the metamorphic rocks complicates the location of mines and unexploded ordnance in this sector of the Korean Demilitarized Zone (DMZ).