The northwestern lobe of Slag Hill, in the Mount Cayley volcanic field. Slag Hill consists of piles of black, glassy, bulbous augite-phyric basaltic andesite flows. Columns have small diameters, variable orientations, and commonly occur as locally radiating masses. This lobe of Slag Hill is nearly flat-topped, with near-vertical, finely-jointed margins, while the eastern lobe has a more rounded morphology.