Where in California did john c fremont explore?

John C. Frémont explored various regions in California during his expeditions in the mid-19th century, particularly in the Sierra Nevada and the Central Valley. His most notable exploration occurred in 1844 when he mapped much of the territory that would become California, including significant areas like the Sacramento Valley and the San Francisco Bay. His explorations played a crucial role in the westward expansion of the United States and contributed to California's eventual statehood.