Mountain Ranges Bordering California's Central Valley

California's Central Valley (450 mi long, 40–60 mi wide) is bounded by two major mountain systems:

Sierra Nevada — Eastern Wall

• Length: 400 mi (north–south)
• Highest Peak: Mount Whitney (14,505 ft / 4,421 m) — highest contiguous US
• Geology: Granitic batholith (Mesozoic), glaciated (Yosemite Valley, Hetch Hetchy)
• Protected: Yosemite, Sequoia, Kings Canyon NPs; Inyo, Sierra, Sequoia NFs; John Muir, Ansel Adams Wildernesses
• Hydrology: West-slope rivers (Feather, Yuba, American, Cosumnes, Mokelumne, Stanislaus, Tuolumne, Merced, San Joaquin, Kings, Kaweah, Tule, Kern) feed Central Valley agriculture & cities.
• Climate: Mediterranean (foothills) → Alpine (crest). Massive snowpack = California's water bank.

Coast Ranges — Western Wall

• Length: 600+ mi (Oregon to Santa Barbara)
• Subranges (N→S): Klamath, North Coast (Mendocino), Mayacamas, Vaca, Diablo, Santa Cruz, Santa Lucia, Transverse (Santa Ynez, Topatopa)
• Highest: Mount Diablo (3,849 ft / 1,173 m) — iconic Bay Area landmark
• Geology: Franciscan Complex (accretionary wedge), serpentinite, sedimentary. Tectonically active (San Andreas Fault system).
• Climate: Coastal fog belt (redwoods), rain shadow (east slopes dry), Mediterranean.
• Protected: Redwood NP, Point Reyes, Big Sur, Los Padres NF, Channel Islands.

Valley Floor Between

Sacramento Valley (north, wetter) + San Joaquin Valley (south, drier) = world's most productive agricultural region (irrigated). Tulare Lake (historic largest freshwater lake west of Mississippi) — now dry, farmed.

The Sierra Nevada is the dominant hydrologic and scenic feature; the Coast Ranges are the tectonic and climatic modulator. Together they create the Central Valley's existence.