General terms:
* Mythological fiction: This broadly describes any fiction dealing with myths and legends.
* Folklore fiction: Similar to mythological fiction, but focused on the stories and beliefs of a particular culture.
* Alternative history: This term applies if the story rewrites existing historical events with a focus on mythical elements.
More specific terms:
* Western tall tales: This term specifically refers to exaggerated stories of the American West.
* Cowboy lore: This term focuses on the stories and legends associated with cowboys.
* Frontier myths: This refers to the myths and legends that developed on the American frontier.
Descriptive terms:
* Legends of the West: This is a straightforward and descriptive term.
* Tales from the Wild West: This evokes a sense of adventure and the untamed nature of the West.
You could also use more creative terms like:
* Whispers of the West
* Legends of the Dust
* The Wild West Saga
Ultimately, the best term to use will depend on the specific content of the book and the tone you want to convey.