Bruce, PKD: Based on my experience last year, I say YES, a season pass from PKD is good at any of their parks, including Canada. Last June I wanted to spend at least 2 full days in the same week at PKD and it was cheaper for me to buy season passes for my family of four. I could have gone to any of their other parks with those passes (I didn't).
SIX FLAGS: the park home pages usually have season pass info...unless their offerings have expired for this year. Prices would be approx twice one daily admission. I have a pass from The Great Escape in Lake George, NY (SF property). I have never been to that park. I will validate/use the pass the first time June 11. It cost $59.99. Regular daily admission there is $32.99. And it will be good at all SF parks. Gives me incentive to get to SFGAdv for the first time (hello, Nitro!) and of course SFNE a few times (nice to see you again SROS!).
(I live in Mass).
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Mother, did it need to be so high?