How about a ride that takes place in a gold mine (I know, it's been done), but what different is that it would have a similiar layout and ride system like the ride "Journey to the Center of the Earth" on Mysterious Island at Tokyo Disney Sea. It is very popular there.
I know it was only one ride, but I have some other ideas.
(1) Also taking from Tokyo Disney Sea, Aquatopia but improved. It could be in the bay near "Golden Zephyr".
(2)Condor Flats needs something else to stick with the aviation theme.That a new ride be built on Condor Flats. Maybe a ride like Rocket Jets but a mixture of old aircraft from the 1930s and 1940s. With an Airline sponsor or Aircraft Maker (Boeing because it took over (McDonnell) Douglas of Long Beach)
(3)A dune buggy adventure. California is home to Death Valley and you could have a four passenger dune buggy that I don't know .....goes all crazy.
(4) Buger Invasion has got to go. McDonald's is not a true California fast food place. Put in an IN N' OUT!. The lines at an In N' Out around California can last hours sometimes.