We did 2 weeks traveling around Colorado for our big summer trip last year. This post covers many of the places we did and I would recommend them. The two places we went that they didn't list was Rocky Mountain National Park and Gunnison(the Grand Canyon of Colorado). See my comments in the below quote:
Thom02099 wrote:
Cheyenne Mountain Zoo this is a great zoo with elephant and giraffe feeding opportunities, we all loved it! Cheyenne Mountain State park is close by and very nice!
Pikes Peak Cog Railway (in Manitou Springs) We just drive up to the peak, skipped the railroad. It was cloudy and didn't see much other than a few trams on the way up, but we couldn't be that close and not go
May Natural History Museum
Cliff Dwellings and Cave of the Winds (close together) We did this and did the tour that you had to climb the ladder and squeeze through a tunnel - will remember this on for a long time. Nice private campground practically across the street with a pool which provided some much needed downtime for the kids
Cripple Creek and Victor Railroad (up in Cripple Creek)
The Canon City/Royal Gorge area (about 45-50 minutes SW of Colorado Springs)
This is just to name a few off the top of my head. H E R E is a link a more complete list of things to see/do in that area. You may want to consider Mountaindale Cabins and RV Resort outside of Colorado Springs as a base camp location. It's a bit out of town, but easy to get to various sights/locations mentioned.
The previous suggestions from others are also very good recommendations. Just depends on where you want to be and how much you want to see, in whatever time you have allotted.
Great Sand Dunes NP is a wonderful place to visit. H E R E is a campground just outside the park that could work for you. There's also a KOA in Alamosa, a bit of a drive, but a good base camp location. We went here. Worth going, but in the middle of no where. We stopped for a few hours on our way out of Colorado, didn't camp in the area. Be aware that there are places that rent sand sleds outside the park that you can bring in to go dune sledding, but the climb up the hill gets tiring.
Either place to stay, you could consider going down to Antonito and doing the Cumbres and Toltec Railroad. Did that with my kids (when they are just a bit older than yours) and they loved it. There's also an alligator farm near the Great Sand Dunes, that could be something different for the kiddos AND the parents. H E R E is the link to them.
Whatever you decide, make sure you get your reservations going ASAP. You will need them.