It sounds like you are describing a situation where a bulldozer was unable to dig through a mountainous area due to an excessive amount of rocks on the ground. The rocks may be too large, dense, or hard for the bulldozer to move or break apart. This can be a common problem in mountainous terrains where the natural landscape is rugged and rocky.

To overcome this obstacle, heavy machinery such as rock crushers, drilling equipment, or explosives may need to be used to break down the rocks before the bulldozer can proceed with excavation or construction work. Additionally, alternative methods such as manual labor or using other types of machinery may be considered depending on the specific circumstances of the job site.