LA to WA state in 3 days

[trickysticks]

Hello,
I need some suggestions for our trip home from visiting family in CA. We are doing the straight shot down (with 4 drivers it should be "easy"), and visiting for 10 days. On the way back (with one less driver), we know we'll be tired from all the fun and wanted to give ourselves a little bit of a break.
We were thinking to stop somewhere around (not in--too pricey) San Francisco, and then in Southern Oregon. We'd like to go the coast for some of the way leaving out of San Bernardino County. I know the coast can take much longer, so we don't want to stay on it the whole time. The 4 kids we are traveling with range in age from 7-16, so any suggestions of things to see that might be fun for them would be great, too. Thanks in advance for any help.