A bull can collect a harem of up to 60 cows. In the fall, rutting bulls bugle or whistle as a challenge to other bulls. The whistle can carry for long distances. Cows will leave the herd for about a week to bear their calves. They can have one or two calves, which weigh up to 40 pounds each.
Calves can walk almost immediately after birth.
Mountain lions and bears prey on the calves. An elk will mark territory by stripping the bark from saplings and rubbing the tree with its chin. These three trees all show signs of elk rubbing them as territorial marking. The tree in the background had tattered bark hanging in strips. The two in the foreground have less damage.