Have you considered Omaha? It's an easy 3-hour drive north on I-29.

The zoo is world-class and many of its best attractions are indoors (aquarium, desert dome, rain forest, IMAX) in case the weather isn't cooperating.

The Durham Museum is also cool--trains, soda fountain, a replica of a town, and probably some other stuff I am forgetting.

You can also drive west about 40 minutes to the Strategic Air Command Museum near Ashland, just off I-80. At the same exit is the Omaha zoo's native animal park and a great state park, Mahoney.

The Old Market, near downtown, has lots of shops and restaurants and a nice Embassy Suites, which I always like staying in with kids. Just north of downtown are a number of new hotels...Fairfield Inn, Hampton Inn & Suites, Hilton Garden Inn, and Courtyard.

Omaha is my hometown (but live near KC now) so if you have any questions, post back! Have fun!

I prefer Tulsa over Oklahoma City, but it depends on your interests. If you wanted to see the Oklahoma City memorial, then it would be higher on your list. But Tulsa is also closer to KC. If you went to Tulsa, you could also make a side-trip to Woolaroc near Bartlesville and have hamburgers at Murphy's or bbq at Dink's. But I'm more familiar with Tulsa and the surrounding area since I'm from around there.

But aside from those, I think the Ozarks (not Branson, but the beautiful surrounding area, particularly in Arkansas) or Petit Jean State Park in NW Arkansas are top choices if you like the outdoors and want that instead of a city-focused trip.

Anywhere that is not tornado territory!

we were thinking of driving to Bella Visa ARK..right near the borders of KS/MO and ARK. That is close. I don't mind OKC. They are fixing up their downtown. Myriad Gardens is opened..and you can rent bikes/kayak on the river front. OKC also has a nice stockyard for shopping and a good meal. We went there last year : )

I think you would enjoy OKC. I would recommend staying at the Hampton Inn and Suites in the Bricktown area. It has a nice big indoor pool with water features for the kids.
It is an easy walk to the river taxis.
OKC has a good zoo, but I think it used to be better than it is now. The zoo is right next door the Science museum.
We also like to go to Norman. There is a great Natural History Museum at OU and an outstanding art museum there too.

Just booked 3 nights in OK city....not sure what we are going to do!