The Question and Answer section for Island of the Blue Dolphins is a great resource to ask questions, find answers, and discuss the novel.
Island of the Blue Dolphin's is narrated from Karana's perspective. Karana is the main character, and she is looking back on the experiences of her childhood.
Check out chapter 14/15.
Karana builds a fence using the skeleton of a whale that had beached on the island many years before.