Mount Cornaccio. Bilberry heaths inhabit these mountain slopes, often in patches amidst the grasslands or interrupted by ski runs. The extent of bilberry heath cover is particularly evident during the fall, when the common bilberry’s leaves turn red and color large expanses of the basin. The slopes that are more exposed to cold winds have prolonged snow cover and the tongues of rock debris that run down the slope are bare, with sparse vegetative growth.