We're doing the first family camping trip this summer as well . . . but we're cheating and taking my parents so they can amuse the kids some of the time! I'm working on making a big, long scavenger hunt that will take them a while - I think I will spread it out over each of the days we are there. Maybe buy a book on trees/plants of your area and see how many you can find? Or do the same with animals? Check in to outdoor games - my kids all love Simon Says, Red Light Green Light and Red Rover. Bring lots of paper, crayons, glue and such and make nature art projects.
We have a nature park two blocks from our house and we often walk down and each child has to find something they didn't notice the trip before. That can be fun anywhere.

Let us know how it goes - I'm a little nervous!

Hiking trails, looking for "wild animals", teach them how to build a campfire, cooking meals over a fire, s'mores, board games....

Have fun

Nature Bingo Cards

http://www.squiglysplayhouse.com/ArtsAndCrafts/Crafts/Bingo.html

Little ditties I learned long ago:
Leaves of three be sure to flee (poison ivy)
Leaves of three let them be(poison ivy)
Furry rope don't be a dope stay away (climbing a tree looks like furry rope on a tree)

Different games
http://www.angelfire.com/ia3/camping2/games.htm

And of course a deck of cards(or 2).

Thanks so much for your ideas! There is a free guided hiking tour one of the days we are there so we were going to do that (my 9 yr old is a nature fact fanatic!). We do have stuff to make smores and a smore type treat with bananas. And I had already set aside crayons, glue, string, markers, etc. We have board games set aside as well as word searches and a deck of cards. We have waterballoons.

Now I will add a scavenger hunt and some activities from the websites you gave me psuedo.

I knew I could count on you girls for some great ideas!! Keep em' coming!

So we got back from camping a little bit ago. The trip was so much fun! The kids loved it and we loved it! I did end up using a scavanger hunt from the websites, but it was more of an open hunt than a specific hunt. Instead of saying to find a leaf or acorn it said things like find something green, find something wet, etc. I just told the kids to work together and not to use the same item twice. It took them a little while to do and it was cute to see what they wrote for each answer after exploring!

I did bring a bag of items like coloring books, crayons, paper, glue, string, scissors, board games, bubbles, football, frisbee, etc. And they all found "walking sticks" our first day and used my sons pocket knife (with our supervision of course!) to carve their names into it.

I also found a smores recipe with a twist online that my kids loved! We did regular smores two nights and then these ones one of the nights. You cut a banana in half and then put mini marshmellows and chocolate chips on the halves and push them together (as much as possible) Wrap them loosely in aluminum foil and put them over the fire for a few minutes to melt the marshmellows and chocolate chips. Then unwrap and use a fork to eat them.

The banana ones are great! I made these as a kid, a little different though: Leave the skin on (I assume you did too), and make a wide V shaped cut along the inside curve of the banana. Stuff the opening with mini marshmallows and choc. chips, (adding chopped pecans or peanuts is good too). Then wrap in foil, tenting the area above the 'stuffing' so it won't stick, then bake in a 350 oven for 10 - 15 minutes. (I don't camp, thus the oven :)
We called them Banana Boats.

Glad you all had a great time!