We stayed at Gros Ventre for 2 nights at the end of July as part of a 3+ week road trip. We had a non-electric site (324) in Loop F. Even in the middle of the summer, we had no problem getting a walk-up site after arriving at approximately 2 PM (though they were running out), probably because it's a pretty large campground and not one of the 'prime time' ones like Jenny Lake or Signal Mountain. We really liked this campground because it is centrally located between Jackson and Moose Junction and the park itself (darn mountain in the way...). It's also very close to the Mormon Row historic district which we happened to drive down ONLY because Google originally mapped us down that dirt road in order to get to the campground (which I would not advise, unless you had already planned to visit Mormon Row). The campground itself was adequate, with nice, level sites, so-so restrooms, and access to the Gros Ventre River for fishing if that's your thing. 

Jackson is a nice cross between a typical just-outside-the-park-boundaries tourist trap town and well-to-do vacation destination so that there is really a nice mix of something for everyone. After spending 4 days in Yellowstone, we were hungry - literally - for something other than really terrible NP food, and thankfully Jackson delivered. We had a fantastic meal (and LOTS of beer) at Snake River Brewing, and I highly recommend it. Cowboy Coffee is an awesome coffee shop and cafe right on 191 (and, bonus, they serve pastries from Persephone Bakery) - their smoothies were a big hit with the kids, and their breakfast burritos were a delicious way to start the day. If you like tea, get the London Fog - delicious.

For hiking in the area, we did the full Taggart Lake loop trail and it was wonderful - I really liked the fact that the trail TO Taggart Lake was so different than the hike FROM Taggart Lake (we went counter-clockwise around the loop). The ranger at Moose did say that several people reported seeing bear along the trail the same way that we went, but we were looking for them (while singing and clapping loudly for most of the hike) and did not see any. There are connecting hikes to Bradley Lake and beyond, though most of the 'beyond' connections get very steep, very fast. We also did the Hidden Falls hike after taking the boat across Jenny Lake, and it was beautiful! The kids enjoyed playing on the rocks and getting to see climbers coming off the mountains.

Out of the 3+ week road trip we were on, we really enjoyed the Grand Teton area - the mountains are gorgeous, and it's just staggering how suddenly they jut out of the landscape. We saw our first moose in this area, and just had a wonderful time all around. We will be back!