Complex sentence: Some Native American oral traditions relate that rather than dying in 1812, Sacagawea left her husband Charbonneau, crossed the Great Plains and married into a Comanche tribe, then returned to the Shoshone in Wyoming where she died in 1884.
Split into simpler sentences: Some Native American oral traditions relate that rather than dying in 1812, Sacagawea left her husband Charbonneau, crossed the Great Plains and married into a Comanche tribe. She was said to have returned to the Shoshone in Wyoming, where she died in 1884.