Plan for a New California State Legislature: A single house –
the California State Assembly, with 500 Members: 1/2 elected from single-member districts by ranked choice voting, 1/2 from regional multi-seat districts by proportional representation

The # of seats from each region is proportional to its population:

Northern California (13 members – 6 from single-seat districts,
7 from multi-seat districts):
Butte, Colusa, Del Norte, Glenn, Humboldt, Lake, Lassen, Mendocino, Modoc, Nevada, Plumas, Shasta, Sierra, Siskiyou, Trinity, Tehama

Gold Country (48 members – 24/24): Alpine, Amador, El Dorado, Placer, Sacramento, San Joaquin, Stanislaus, Sutter, Yolo, Yuba

San Joaquin Valley (39 – 19/20): Calaveras, Fresno, Inyo, Kern, Kings, Madera, Mariposa, Merced, Mono, Tuolumne, Tulare

Bay Area (98 – 49/49): Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano, Sonoma

Central Coast (19 – 9/10): Monterey, San Benito, San Luis Obispo, Santa Barbara, Santa Cruz

Greater Los Angeles (181 – 91/90): Los Angeles, Orange, Ventura

Inland Empire (58 – 29/29): Riverside, San Bernardino

San Diego Border (44 – 22/22): Imperial, San Diego