Hi, we are from Australia. We did a 6 week roadtrip in june/uly 2011, and spend time in yellowstone with our 4 kids then aged 8, 6 and 3 1.2 year old twins in a 31 ft motorhome.
My suggestions would be...
- campground - my suggestion would be to stay somewhere inside the park. You will be doing enough driving around yellowstone as it is with the kids, so i would avoid extra miles by not having to drive into the park everyday. We stayed at Madison, only because we couldn't get reservations at the more central Canyon campground (which also has a laundry! )
- What our kids enjoyed - mostly wildlife spotting. The geysers, mudpots etc and fishing (make sure you get a license) and the many waterfalls.
The kids loved sitting around the campfire at night making smores.They also loved waiting for old faithful to erupt while eating ice cream!
- I would second seiler birds notion of adding Grand Teton National Park/Jackson to your to do list. We spent four days their and it was still not enough! You will see lots of wildlife, gorgeous mountains, just beautiful. One highlight for us in Jackson was visiting the BAR T5 covered wagon dinner and show. Great family evening, the kids loved the ride out to the dinner in the covered wagons which got "stormed by indians"! Yummy food and great entertainment which envolved the entire crowd with crowd participation (and kids). Resonably priced.we stayed at gros ventre (gro vont) which is non reservable, but like seiler bird said, no problems getting a spot here. saw moose on the drives in and out reguarly.
- We also spent 3 days in cody, which can be done as a side trip, beautiful drive out there. Theres the Buffalo Bill Museum (huge) we visited this, but its so big the kids got bored after a while, which is understandable considering the little ones, but i recommend this anyway. We stayed at the cody koa, kind of expensive, but has a pool, hot tub, hay rides for the kids, shuttle into the nightly rodeo, jumping pillow, ice cream social, pancake breakfasts, games room, etc we just found it great for the kids, and really friendly.
We are heading back for another trip this june july, and are heading back to spend more time in yellowstone and grand teton national park.
This time we are going to do a family float/small white water dinner trip in jackson/gtnp, jenny lake, inspiration point, and in yellowstone, visit the grizzly and wolf discovery center in west yellowstone(lots of kid stuff to do and see), see more of some of the places we flew by last time, like tower, lamar, mammoth hot springs and more trails...
we are going to check out a couple of these suggestions from the list below.
Easy hikes for kids?
Geyser basin trails?
? Mud volcano loop(north of lake/fb)
? West thumb geyser basin
? Norris back basin
? Fountain paint pots
? Black sand basin
Geyser Hill out to morning glory(check with visitor centre when it is going to erupt and go in that direction first)
Observation Point Loop Trail-(hike above to look down on old faithful and all of the area. Kids like seeing solitary geyser as it erupts, if you stay there a few minutes.
Lake Area Hikes
? Storm Point Trail
? Natural Bridge Trail
Canyon Area
? Uncle Tom's (kids love stairs) you'll never forget doing this
? Cascade Lake Trail
? Grebe Lake Trail
Old Faithful
? Lone Star Geyser Trail
? Fairy Falls Trail (easier than mystic)
? Mystic Falls Trail
Norris Area
Ice Lake Trail (can use pram)
West Yellowstone
? Two Ribbins trail (can use pram)
Mammoth
? Beaver ponds loop trail (ages 6 and up - can do it if they hike often- about 5 miles)
? Wraith Falls - easy 1 mile
I hope you have a great family holiday and i hope some of this has helped.