Oregon campgrounds where dogs can't hear fireworks?

Hi everyone, I was wondering if anyone knew of a good campground within 50 or so miles of Portland that is far enough away so that the noise from fireworks can't be heard over the 4th of July holiday?
I have 2 senior Mastiffs with heart problems, and my female is extremely sensitive to popping sounds.
I have decided to take the dogs out of town camping in our TT this year instead of subjecting her to the terrible fear and anxiety, especially now that her heart is enlarged.
Any suggestions would be greatly appreciated, thank you.