So Prop 21 didn't pass, but the California State Parks Foundation (not the parks themselves, but a nonprofit that supports them) has a benefit this weekend featuring Hollywood films shot in California Parks.
California State Parks starring in Hollywood Films

Saturday's at Paramount Studios with
Return of the Jedi (already sold out, apparently) with Q&A with Mark Hamill
Race your speeder through the redwoods parks.
M*A*S*H (both film and a few TV episodes) both shot in Malibu Creek (you can hike out to the set, but there's not much but a rusted jeep there) Elliott Gould and Father Mulcahy in attendance.

Sunday's at Fox with
Spartacus (partially shot at Hearst Castle)
Planet of the Apes (1968) partially shot at Malibu Creek and Point Dume.

The site also has a nice list of the parks, detailing the movies they've been in. I've been to Egypt! Or at least its body double for the Mummy at Red Rock Canyon.