Kioga of Unknown Lands — William L. Chester

This is the fourth and last of the epic adventures of Kioga, the Snow Hawk, in the wilderness of the unknown Arctic continent of Nato'wa, homeland of the American Indian. Here Kioga comes to his ultimate challenge as he finds a lost land within a lost land, as he encounters the wonders of the city of the mammoths, and counters the schemes of those who would despoil mankind's last wilderness wonderland.