Hope your kids haven't watched Parent Trap. laugh Sorry, couldn't resist.

If it's any consolation, 18 is a really nice site with a creek down the middle of it. Great place for kids to play. It's likely too small for your group, but I thought the furthest south site on the east side of the creek was the best.

Trail to it from Fremont is easy. I don't recall any trails branching off of it. There are some past 18 to the west that you could make into a loop of varying distance.