Known primarily among Marines undergoing training at the School of Infantry at Camp Pendleton, California as the least desirable place to hump a pack. Tops off at "Recon Ridge". Named as such because when you are going up, your thoughts consist of little more than "motherfucker..."
PFC. Smith: Fuuuck, we're doing what for PT today?
PVT. Johnson: A pack run up Mount Motherfucker.
Stronger than damn, stronger than god damn, and yes, even more powerful than god damn fucking, god damn motherfucking is for when you really god damn motherfucking mean it.