I was looking at the calendar of events
for William O'Brien State Park
and on October 18th they are having "Happy Falloween". Here is their discription: Decorate your campsite at the park. There are different categories with prizes. Kids can trick or treat in the campground. Sites with pumpkin cards will participate. Judging will begin at 7 p.m. for the pumpkins and costumes. Be sure to join us for a night hike. There will be different hikes for different ages. After your hike, storyteller Dwight Wilcox will share some "tall" and "short" campfire tales. A marshmallow roast will end the evening.
This sounds like a good camping trip to bring your kids with. It might get chilly but nothing that extra layers can't fix.
If you are interested in camping that weekend please let me know. Rather then get a group campsite I think it would be nice to get drive-in sites, maybe even an electric site so we can have lighted decorations.