Shell large, exceeding 2 inches (56 mm) in diameter and 1½ inches high. The shell is rugged but not regularly ribbed. In shape it is conic and leans toward the carina, the wall of which is nearly vertical. There is very little erosion except at the orifice, the edges of which are usually broken. One of the most distinctive features of this subspecies is the glossy appearance of the narrow radii which retain some of the dark-brown epidermis that has been worn off the remainder of the shell. The parietal tubes have cross-septa from summit to base.
Usually white but occasionally the shell may be completely covered with brown epidermis. Interior of the cover-plates white.
Aleutian Islands, southern coast of Alaska and south to Puget Sound. In British Columbia, specimens have been taken at Seymour Inlet, Wentworth Island, Brotchie Ledge, and William Head (Vancouver Island). From intertidal zone to 1,115 feet (338 metres) in depth.
Balanus rostratus alaskensis is frequently dredged up in groups, the younger individuals sometimes growing on top of the older ones, which in time become smothered.