The pelage is much longer in winter than in summer. Both sexes have a crescent-shaped gland behind each horn that increases in size during the rutting season. The appearance of both sexes is much alike except that males are considerably larger than females. The horns of an average adult female are equal in length to those of an average adult male but are more slender. Sexes are extremely difficult to differentiate in the field unless the female is accompanied by a kid.
Goats are usually quite docile and their usual gait, even when alarmed, is a deliberate pace.
Mountain goats mate in November and December. They do not collect harems, but some battling occurs as males often show puncture wounds, particularly on the rear quarters. Adult males are segregated from other age classes except during the rut. They may form small bachelor groups, especially in summer. Females with kids and immature animals are generally found in groups but may form larger nursery bands in early to mid-summer.