@Nyboy First question, how old were the girls, second question, was the area they were let out safe? The world today is not the safe place it was when I was growing up, heck we use to take a sandwich and disappear for the whole day, arriving home in time for supper, or maybe not

. We were definitely home before it got dark.
When I was10 my friends and I would take a lunch and head for the beach for the day it was 5 miles away, if I remember correctly took us about 2 1/2 hours, parents didn't give it a second thought. When I was 4 I went to a prekindergarten school across town, my dad dropped me off but I took a bus home all by myself, mind you the bus driver on that route most days was a friend of the family

.
Unfortunately the world is not a safe place anymore, parents that care and keep a close eye on their kids still worry until their kids are safely back home. You should know where your kids are at all times, and yes check up on them to see if they are where they said they would be, the older they get the sneakier they can be but, always let your kids know you will be checking up on them, yes there will be some resentment but if they're warned ahead of time there's less chance they'll try something.
Ask me how I know this, our kids didn't have a chance, we knew exactly what they were trying to get away with, been there done that

, they never did figure that one out. Also stay united if one parents says no even if you don't agree with it stand firmly together, Talk about it later but not in front of the kids.
Our daughter found this out the hard way when I said no and then had to go out to a PTA meeting, she asked her father and he said yes, she was very embarrassed when her father arrived at her friends house and read her the riot act, she never tried that again.
I'm sure glad I'm not raising kids today, so much can go wrong in a blink of the eye, Kudos to those who are doing it, I really don't think I could do it and stay sane.
Annette