pillow line
n.— «For most of the run, the camera is completely covered in snow as Douglas expertly launches from knoll to knoll. These knolls are called “pillow lines”—massive rocks that are covered with a ton of snow.» —“Heli of a way to reach the peak” in Mica Lodge, British Columbia Toronto Star (Canada) Oct. 14, 2007. (source: Double-Tongued Dictionary)