A highwall is the sheer, unexcavated cliff left behind as a surface mining operation advances through the earth. It consists of the exposed overburden and the mineral seam being extracted. Because these towering faces can reach hundreds of feet in height, they pose significant rockfall and collapse hazards, requiring careful scaling and monitoring to protect personnel working below.
Heard on the job
Keep the drill rig at least fifty feet back from the highwall edge until the geotech clears that fracture zone.
Insider tip
Operators often leave a safety berm at the top and base of a highwall to catch loose material before it hits the active pit floor.