What metaphors are used in Ishi: Last of His Tribe by Theodora Kroeber?

Black Rock is a secret lookout point where Ishi goes to watch the Monster as it travels through the mountains, and to pray. It stands three times taller than a man, and Ishi likes to climb it. Ishi treats this place as a special secret, and nearly no one knows of its location or significance to him: it is a symbol and metaphor of the personal sacred.