Yeah I have been there , bad news I was 11 so can’t tell ya anything of great value BUT OLD FAITHFUL was really cool to see.

I’ve been to both.
Old Faithful was cool, butI was underwhelmed by both parks.
I’ve been to Yosemite many times, so I guess I was comparing.

I’ve visited Grand Teton. The area is impressive, and those jagged peaks are quite a sight. For my money, though, I’d say head on down to Utah and see Arches, Bryce, and Zion. Spectacular.

Just promise me you won’t go anywhere near Angel’s Landing.

I haven’t been to either park.

I’ve seen the eastern wall of the Sierra Nevadas and I hiked up to the top of Mt. Whitney.
I’ve also seen some of the Himalayas and trekked around the Annapurna massif.

Even though the mountains of those ranges are taller than the Tetons, they both have foothills blocking the views of their bases.

However, from what I’ve seen of photos of the Tetons, they’re not fronted by any noticeable foothills, which is why they’re so magnificently prominent as they rise abruptly above the green plains and blue lakes before them.

I’d love to see the wildlife that inhabits Yellowstone.
If I went there, I’d see if there are any tours where one can see and record the grizzly bears, buffaloes, wolves, eagles, and moose living there.
Also, the fastest animal in the western hemisphere, the pronghorn antelope (which has been clocked at 61 MPH), can be seen taunting whatever predator tries to catch it.

Briefly visited Yellowstone in 1997 (late August/early September). We camped, and I recall having to sign a waiver saying that we understood the risks (bears). It was great. It was elk mating season, so we heard the eerie mating calls all night.

We saw lots of elk and bison, did some light hiking, saw Old Faithful, and the park wasn’t very crowded. But I understand that things are quite different now. I’ve heard that crowds can be huge.

I have been to both. They are very close to each other so I suggest experiencing both. Jackson Hole is breathtaking year round.
What are you planning on doing when there? Are you a hiker or are you just driving and observing?
They are both beautiful but it really depends on your plans. What time of year are you doing this will also play into your experience.
Personally I love both, but have had different experiences in each. Hiking and natural beauty is abundant in each.

My family visited both when I was a child. I love the mountains, so I remember being awestruck by the Tetons. There was much to see in Yellowstone, and I enjoyed it a great deal.

My family went to Yellowstone but I don’t think they went to Grand Teton. I am reading that Yellowstone is great but Grand Teton is awesome and doesn’t get as much publicity.

If we go, it would be in August.

I am not a big hiker. I have a permanent ankle injury from a car accident from about 20 years ago, so I’m limited in that way. I can take a good walk but nothing heavy duty.

I ordered guide books from the internet from Wyoming and Montana tourism sites. I was looking at Jackson Hole on TripAdvisor yesterday.

What’s your starting point, @jca2, and how are you traveling? Are you driving to these destinations or flying in from somewhere?

Plan on a week.
Go after June both places can have snow; early snow in August! Last time in Grand Teton / Yellowstone was August 1977; we had to go out on a different road then planned, it snowed 18 inches in the Northeast corner of the park. Went two other times in 1950’s in July.

@Jeruba: If I went, I’d drive from NY. I am looking for a good distanced road trip to avoid flying. I’m not afraid of flying but my daughter likes road trips and I find them so easy, because the car becomes like a big closet and you don’t have to deal with schedules and luggage requirements and stuff like that. It’s just throw everything in the car and head out. We rent an SUV when we take a long distance road trip like that.

In 2012 my son and I traveled together by car from Chicago home to Northern California. The route zigzagged north and south to hit as many national parks as possible.

In three weeks starting from Chicago, we took the northern route through WI, MN, SD, WY, MT, ID, UT, NV, & CA. Lots of fabulous scenery on that route, lots of parks. And the (gasp) Going to the Sun Road, which I never want to see again. Even a relatively short stretch of that itinerary would be amazing. Not to mention Wall Drug in Wall, SD. I could skip the crossing of the Nevada desert, though.

I hiked for a week in Grand Teton last year. As a desert dweller, my absolute favorite part was wading into the pristine alpine lakes, and there are nice spots along the Jenny Lake trail to the right and not far from the main parking area. Jenny Lake also has a ferry that will take you to a point that’s about ⅓ of the circumference of the lake from the main parking area. There will be a line and a wait on both sides.

The park is 10 miles north of Jackson, and traffic can sometimes be significant.

South of Grand Teton is the Laurence S. Rockefeller Preserve. This is also a worthwhile stop, but I remember we had to wait a little while for parking. If you go counterclockwise around Phelps Lake, you’ll come across a giant boulder that the kids like to dive from, which is fun to watch. Phelps has more stuff growing in the lake bed, so it’s not as nice to wade in as the lakes in Grand Teton park.

Another option in Jackson is to raft the Snake River, and there seemed to be plenty of outfitters/guides.

Over the Teton Pass (mind the 10 percent road grade) into Idaho, stop at the Victor Emporium for a huckleberry shake (you can get them other places too). Nearby, in Driggs, there’s a drive-in theater called The Spud and a nice restaurant and small fighter plane museum. 30 minutes further west, you can enjoy a very affordable soak with the locals at Green Canyon Hot Springs.