Which present day states were once a part of Alta California?

Alta California, a region under Spanish and later Mexican control, primarily encompassed present-day California. It also included parts of Nevada, Utah, Arizona, and portions of Colorado, Oregon, and Wyoming. The area was defined by its vast coastline and varied geography, reflecting the diverse ecosystems and cultures that existed before U.S. annexation. Following the Mexican-American War and the Treaty of Guadalupe Hidalgo in 1848, these territories were ceded to the United States.