Get yourself heading to I-40 in California and then I'd highly recommend taking Hwy 395 north from just west of Barstow. It's a gorgeous drive and you won't have the California traffic that you would find along Hwy 99 or I-5 on the western side of the mountains. There are many public campgrounds. Stop in Lone Pine and do a day trip into Death Valley. Lone Pine is also where some famous old westerns were filmed. Neat history. Try June Lake along 395 for one great area to explore. Stay in Lee Vining and do a day trip to Yosemite and also tour Bodie Ghost Town.