Thinking of heading to Colorado for about 2 weeks - end of June. Husband and 3 kids ages 9, 10 and 10. We did the Utah 5 last year and they don't want to hear the word hike! We want to do a few days in Denver (would love suggests for this part too - kid friendly places - they like museums, parks or just fun areas). Then we'd love to get out into the mountains maybe some lakes, water activities, hotels with great pools, horseback riding - we'll still do some hiking, but trying to keep the kids busy with other activities. It's totally last minute planning, but I only pictured Colorado for a skiing trip for us - not summer!

You're traveling this June - like 3-4 weeks from now, so your first move should be to see where if anywhere you can find accommodations. Things near parks, lakes, resorts - the sorts of places you listed - book up pretty far ahead.

Yes - definitely late to the game. I just have no idea where to start. I can find places in Denver.

All of the big ski resorts have activities beyond hiking. I'm most familiar with Vail... You can take mountain bikes up the mountain in the gondola and coast down on the service roads or ride the bike paths along Gore Creek and around the town. Adventure Ridge at the top of the mountain has a zip line, a bungee trampoline, climbing wall, coaster ride, mini golf, etc. There's an indoor ice rink in town with public skate times, and there are performances most summer nights at the Gerald Ford Amphitheater. There is flyfishing (lessons, equipment rental, tours), and a lake a short drive from town. Several hotels and condominium complexes have pools. It's an easy day trip from Vail to Leadville where you can ride a vintage train up into the mountains.... Back in Denver, we've had no trouble buying same day tickets to a Rockies game.

Yoru kids are a great age to enjoy dinaosaurs. Anc Colorado Springs and the Air Force Academy would be a good stop. Just west of CO Springs is Woodland Colorado that has a very nice dinosaur age museum and exhibit even with a lab where they are sorking on fossils.
So get a map and stick a pin in
Denver--stay a few days and do some things--zoo, botanic gardens, museums (natural history and art--which has a wonderful native American exhibit).
Head south, maybe stopping in Morrison (stick a pin in your map) on the south edge of Denver whree there is a dinaosaur exhibit (and Dinosaur Ridge--a road to drive on and stop and several exhibits).
Go to CO Springs and Woodland (stick a pin in your map)
You have a good amount of time so I would continue dirivng sout and west--see the Great Sand Dunes and then head for Durango and go to Mesa Verde. Stick some mor pins in your map.
If this is going to be a destination make reservations right now.
Anyway the other wonder of Colorado you must not miss is Rocky Mountain National Park so make a loop coming back toward Denver and enter the Park from its Western entrance. .

Just west of CO Springs is Woodland Colorado that has a very nice dinosaur age museum and exhibit even with a lab where they are sorking on fossils.

That would be Woodland Park.

Agree that the kids might enjoy the Sand Dunes, but keep in mind the sand can be very hot, so plan your day accordingly.

Rocky Mountain National Park is absolutely heaving in the summer and requires timed entry, so you'll need to plan well. There are so many other places to visit in CO, I'd give RMNP a miss.

Some kid centric suggestions:

Cheyenne Mountain Zoo (Colorado Springs)
Royal Gorge and Buckskin Joe (Cañon City - I loved Buckskin Joe when I was a kid)
Elitch Gardens (Denver)
Garden of the Gods Segway tour (Colorado Springs)
Colorado Railroad Museum (Golden, west of Denver)
Drive up Pikes Peak or take the Cog Railway (between Colorado Springs and Woodland Park)
Hammonds Candy Factory Tour (Denver)
Aquarium (Denver)
Rocky Mountain Zipline - (Conifer, west of Denver)
Fishing - https://www.uncovercolorado.com/best-fishing-colorado/
Durango Narrow Gauge Railroad - Durango in the SW of the state - https://www.durangotrain.com/
White water river rafting - (Buena Vista - about 90 minutes west of Colorado Springs)
Hot springs (Cottonwood & Mt Princeton near Buena Vista, Salida, Steamboat Springs, etc)

Or how about a rodeo?

https://www.colorado.com/articles/be...odeos-colorado

Or a visit to Flying W Ranch (Colorado Springs, another favorite from my childhood):

https://www.flyingw.com/

Also the usual tourist suspects of Seven Falls:

https://www.broadmoor.com/adventures/seven-falls

And Cave of the Winds:

https://caveofthewinds.com/

Both west of Colorado Springs.

In Denver view colorful butterflies in the Butterfly Pavilion; ride a narrow gauge steam train at the Colorado Railroad Museum.

In Colorado Springs go wander around Manitou Springs eating saltwater taffy exploring art galleries and the historic Cliff House hotel; and eat and shop in Old Colorado City;

Or visit a gold mine - Cripple Creek - about a hour from Colorado Springs - a former gold mining area, now mostly casinos, but very pretty and good for a walk through, as is nearby Victor and it's gold mine. The donkeys roam free in Cripple Creek in the summer months. Kids might get a kick out of that.

https://www.goldminetours.com/

https://victorcolorado.com/

And how could I forget Bishop's Castle (near Rye):

https://www.bishopcastle.org/

I'd think the kids would go bonkers there.

I see someone above mentioned Mesa Verde NP. I heartily second the advice and suggest you book accommodation in the park for two nights and sign up for at least one of the ranger tours to the cliff dwellings. I think kids would be fascinated by the ancient history.

OMG!! It's like the place in St. Louis! They would LOVE this!!
(Bishop Castle)

Yeah, figured they might.

The advice to book IN Mesa Verde is right on and for this trip has to be done immeiately. It is a true wonder of the world and interesting to kids because you are climbing around.
About the dinosaurs and Denver. It is interesting to note that Denver was once uderwater--Denver's oceans.--which iswhy the dinosaur tracks along Dinosaur Ridge happened. The mountains came later. They were walking in mud.
I 25 south to CO Springs has the remnants of prehistoric volcanoes--those mounds along the road.