3. Monterey Bay
Monterey Bay is a popular tourist spot just south of San Francisco: home to a major aquarium, Cannery Row (made famous in John Steinbeck's novel) and Fisherman's Wharf; nearby you'll probably see sea lions, harbor seals and sea otters. Great spot to try sea-kayaking! The spring break months of March and April are whale-watching months as well.
Put together an affordable getaway on the coast halfway between LA and San Francisco: low-cost attractions include the Morro Bay Natural History Museum and San Luis Obispo Children's Museum; economy lodgings options are available too. Plus, free fun at beaches that have tide pools, or piers, or sand dunes... See seals, sea lions, sea otters, and even elephant seals (March to December) at one beach breeding ground. Also free is a weekly night-time farmer’s market with live music, performances, bouncey houses for kids. Also in the area: Hearst Castle for sightseeing, and surfing beaches.
Mammoth Mountain is, well, mammoth: over 11,000 feet high at the summit. Mammoth is a great destination for spring skiing: it's known as a top spot for late season snow, and sometimes stays open right through June. Look for "Kids Ski Free" pricing. Mammoth Mountain is 264 miles east of San Francisco, and gets cheap flights from SF, LA, Reno and other cities.
This upscale ranch resort is a 10,000-acre working dude ranch is in the Santa Ynez Valley, 2 hours north of LA, 30 minutes north of Santa Barbara, and near the quaint Danish town of Solvang. Activities include fly-fishing, kayaking, sailing on the lake, archery, golf, 50 miles of riding trails, a ropes course, kids program, hiking, biking. Bonus points for no tv's in rooms.
The trendy Huntington Beach area, south of LA, bills itself as "Surf City USA", and offers beach hotels and surfing lessons, as well as reasonable proximity to Disneyland. Left: the Hyatt Regency Huntington Beach is one option for a family stay.
A great idea for spring break with younger schoolkids: LEGOLAND California -- south of Anaheim/Disneyland, and north of San Diego-- has 128 acres, and much of what's in it is made of LEGO blocks. Designed for ages two to twelve, LEGOLAND has a coaster, "dark ride", and other rides, mini-lands such as Ancient Egypt (all made out of Lego, of course), and many more attractions.
Southern California temperatures should be lovely during spring break, and About.com's Guide for California Travel has a San Diego planner with highlights for families such as the San Diego Zoo and Wild Animal Park.
Seeing animals in their natural habitat is even better, and if your spring break is early, you might catch some Whalewatching in San Diego: in March, whale mothers travel north with their babies.
Families will also like The New Children's Museum; trolley tours; and Balboa Park, which has a dozen attractions.