"Ishi: Last of His Tribe" is a slightly fictionalized account of the life and death of Ishi, the last of the Yana People in northern California. The book was written by Theodora Kroeber, whose husband, Alfred Kroeber, met and worked with Ishi at the Museum of Anthropology at the University of California. Theodora Kroeber wrote the narrative based on her husband’s notes, though she never met Ishi herself.

Ishi was born in approximately 1861 or 1862, and his father was killed, as were most of the Yahi Indians, in a series of slaughters by the white miners who invaded California during the Gold Rush. In the beginning of the book, Ishi is thirteen, and is living in a hidden village called Tuliyani, in the foothills of Mount Lassen, known to Ishi’s people as Waganupa. There are only seven of the Yana People remaining, including Ishi, Mother, Elder Uncle, Grandmother, Grandfather, Timawi, a young Bushki Indian, and Ishi’s cousin, Tushi.

Ishi often goes to his secret hiding spot at Black Rock, which overlooks the valley below, and where Ishi can watch the white man’s train, which he calls “the Monster,” as it passes through the mountains. At thirteen, Ishi begins sleeping in the men's tent, or watgurwa, and begins the selection of wood for his first adult hunter’s bow. While at Black Rock, Ishi has a close encounter with the saldu, or white men, and tells Timawi about it, as he is older than Ishi and would know what should be done. Timawi tells Ishi to not set traps so close to the trail, because it is important that the saldu not know that some of their People still live.

When the fall arrives, Ishi’s People begin preparations for the great Harvest Feast, and for the winter ahead. The feast consists of deer, elk, ducks, geese, grapes, and other plants and herbs collected by Tushi and Mother. During the winter, Ishi’s small tribe subsists on less and less until the return of spring, and Ishi’s grandparents, referred to as the Old Ones, relate stories over the fire of the Gods and Heroes of the Yahi People. Ishi’s Grandfather also relates the story of the arrival of the saldu and of the massacre of Ishi’s People.

Ishi has a prophetic dream one day at Black Rock, in which Ishi swims up the River Daha and to the Outer Ocean, to the Land at the End of the World. When spring finally arrives, Ishi and Timawi hunt and fish the salmon that come upstream to spawn, while Mother and Tushi collect plants and herbs to be eaten and used for tools.

After three years pass, Elder Uncle takes to calling Ishi “Younger Brother,” as he has grown even taller than his uncle. Ishi takes a journey through the Yahi World, exploring the villages where he was born and where his people died by the “firesticks” of the white men. Upon his return from Ancestor Cave, Ishi’s thinking becomes that of a man.

While gathering brodiaea bulbs by the creek, Ishi and Tushi encounter more saldu, and Ishi saves Tushi’s life by shooting a white man as he attempts to lasso Tushi. The man escapes, and Ishi’s family decides it is no longer safe to stay in Tuliyani, as more saldu will surely come for them. Timawi convinces Elder Uncle to allow him and Ishi to seek out a secure cave, high on Waganupa.

While camping in the woods during their search, Ishi wakes to find Timawi missing. He follows Timawi’s trail to discover that Timawi lit a fire in the storehouse in a nearby saldu village in revenge for the massacre of his People. Timawi was cornered by saldu and dogs and escaped down a ravine, but died from the fall. Ishi carries the body of his friend to Ancestor Cave and performs the burial rites there before returning to Tuliyani.

Ishi continues to search for a new home for his tribe, and finally finds Wowunupo-mu-tetna, which meant the Grizzly Bear’s Hiding Place. Wowunupo is a cave set in the sheer face of a canyon, and Ishi, Mother, Elder Uncle, Tushi, and the Old Ones make the dangerous journey up the mountain. After two years at Wowunupo, Grandfather dies, followed shortly after by Grandmother.

After many years have passed, Ishi and Tushi are no longer young. Mother becomes sick with an illness that makes her ankles swell in pain and makes walking impossible. At harvest time, Ishi and Tushi encounter more saldu as they make their way through the mountains digging a ditch. The saldu discover Wowunupo and Ishi’s mother, who is unable to flee upon their arrival. The saldu who speak with Mother do not harm her, but the village is ransacked and everything taken. Ishi and Mother stay in hiding, and Ishi goes to find Elder Uncle and Tushi, who had escaped along the creek bed. Finding only Tushi’s shell necklace, Ishi realizes that Tushi and Elder Uncle were likely swept away when the creek overflowed. Deep in the winter, Ishi’s mother also passes away, and he carries her to Ancestor Cave, where he laments her loss and the loss of his People. Left alone and starving, Ishi leaves the Yahi World to seek the Trail of the Dead to follow his Ancestors.

Instead, Ishi finds himself by a slaughterhouse near the current city of Oroville, California, and is taken by the local sheriff and housed in the town jail for Ishi’s protection. An anthropologist from the University of California comes to meet Ishi and can speak some of the Yana language. Ishi and the man he comes to know as “Majapa” become friends and Ishi accepts Majapa’s invitation to come live with him at the museum.

Ishi takes the Monster, or the train, to San Francisco, where he lives at the museum for several years. There, he rebuilds the tools of his people, speaks with visitors, and befriends the staff and others. Ishi comes to know a boy there who is the son of a doctor friend of Majapa’s, and he teaches the boy, whom he calls Maliwal, to build bows and arrows, to hunt, and to fish. After many attempts to convince Ishi to take him to see Tuliyani and the Yahi World, Ishi finally agrees and accompanies Majapa and Maliwal to his homeland. Afterward, he returns to the museum, where he dies in 1916, surrounded by his new white friends.