the bear II wrote:
Along I-5 there isn't much of interest until you get to Sacramento. The capitol building, railroad museum, the river area...etc.
After leaving Sacramento other than some forests there isn't much until you hit Lake Shasta.
Same thing as you get into Oregon if you stay on I-5
Like others have posted a better sight seeing trip is up HWY 1 or HWY 101. Lots more to see and do. Hearst Castle, Redwoods, Fort Bragg, Skunk Railroad...etc.
California Highway 1 is still closed in the Big Sur area and isn't scheduled to open till October 1 of this year.
It will be over a year of closure by then.