Lions have an important role in the park ecosystem because they prevent the overpopulation of deer. A mountain lion attack is an extremely unlikely event. There is a far greater risk, for example, of being struck by lightning.
Attacks are always possible, however, as is injury from any wild animal.
Watch children closely. Never let them run ahead or lag behind on the trail. Avoid hiking or walking alone. Do not leave pets or pet food outside and unattended, especially at night. Pets can attract mountain lions into developed areas.