First of all, Vail is 2 hours from Denver and 3-4 hours from Colorado Springs (depending on the route you take).

I assume that your reference to the Rockies meant Rocky Mountain National Park west of Estes Park not the Colorado Rockies baseball team (though a game would be a possibility if the team is in town). The park has lots of hikes and Estes Park is fun--though somewhat touristy and crowded in the summer. Here is their website--http://www.nps.gov/romo/index.htm

If you want to explore other areas of the Rocky Mountain here are places you can find activities you mentioned and a few others.

Trains
Georgetown Loop--west of Denver--http://www.georgetownlooprr.com/
Leadville--http://www.leadville-train.com/

gold mines tours--some also offer gold panning--fun for kids--here are three
Mollie Kathleen--in Cripple Creek-http://www.goldminetours.com/Home.html
Argo in Idaho Springs--west of Denver--http://www.historicargotours.com/
Country Boy--near Breckenridge http://www.countryboymine.com/

You could also go river rafting--we have always gone with River Runners on the Arkansas near Buena Vista--but there are lots of other companies on other rivers http://riverrunnersltd.com/

How about a stop at a hot springs--Mt. Princeton Hot Springs has some nice pools http://www.mtprinceton.com/ It is close to the river rafting on the Arkansas and there is nothing better than soaking in the warm water after a raft trip.

I do have a question--if you've been to Colorado Springs several times, why not consider skipping it and visiting other parts of Colorado this time (it's a big state).

Since you say "you know what to do", I will ask if you know about the excellent dinosaur museum/exhibit about 20 miles west of CO Springs at Woodland Park. I think you AND your boys would enjoy it immensely. It is also a laboratory where they are cleaning artifacts for the future. Definitely DON"t skip it!!
The gold mine tour was good fun for our 9 and 11 year olds last year.

If you wanted to pursue the dinosaurs a bit more, there is Morrison very close to Denver which also has a dinosaur exhibit, and Dinosaur Ridge nearby to look at footprints on the side of the road.
South of CO Springs is Royal Gorge--a beautiful place--and more dinosaurs.

Thanks martym! Can't skip COS--business trip. Trying to add some family fun on the back side!
Gretchen--we are not into dinosaurs, but you may have talked me into driving the boys there (Woodland Park) during one of hubby's morning meetings!?!

Do any of the ski resorts offer year round skiing? Anywhere to see snow in June? We see snow about once every 5 years. We played on an icy glacier in OR last year in July. I know it's the wrong time of year for skiing, but thought I'd ask--if it is convenient. (And we will probably skip rafting due to inexperience with spring snow melt unless someone knows of a float/class 1 or 2 place during that time of year-late June!)
I think martym has a number of sites for me to research that look perfect and will fill our few days!
thank you!
abcdk

No year round ski resorts--Arapahoe Basin might still be open when you are here. http://www.arapahoebasin.com/abasin/Default.aspx

As to raft trips, check with the rafting company about the availability of float trips. http://riverrunnersltd.com/arkansas_river_family_float_rafting_trip_colorado.shtml

I really recommend the dinosaurs. if you haven't seen this type of exhibit, you might be surprised.

The Pike's Peak Cog Railway would be a fun activity to do with your boys while your husband is in meetings.

www.cograilway.com

I would go to visit your friends in Vail. Take 24 to 9 to 70 to Vail, which is a pretty drive. Lots of hikes in the Summit County area that include old mining and town sites. Breckenridge has an alpine slide the boys would enjoy and a cute town to wonder around. Rafting, fishing, water sports galor. Let your local friends be the guide. Fly into Colorado Springs and out of Denver, unless it is cheaper to do a RT out of one or the other. Have fun!

Arapahoe Basin is scheduled to close June 6.

I was there Monday and it's getting thin. With the big warm-up coming this weekend, I can't imagine it will be ski-able much longer.

There should be snow on St. Mary's glacier in June. It's off I-70, near Idaho Springs.

From Wikipedia:
"Saint Mary's Glacier is a perennial snowfield located at 11,000 feet (3,000 m) in the Colorado Rockies north of Interstate 70. It is approximately 10 acres (4 ha) and offers year-round skiing and snowboarding. There are several hiking trails that go around and through the snow field. Although not technically a glacier because it does not flow, The term "Glacier" is merely part of the place name. In the 1950s a housing development was created near the glacier and is called Alice. Currently, the snow field has not receded in the past years due to northern exposure and recent high snowfall."

http://hikingincolorado.org/stmary.html

There will always be plenty of snow and ice (glacier) up here, anytime you come, if you only see snow once every 5 years. We just got an inch of snow Wednesday night. There is a pay parking lot up here, St. Mary's Glacier Paid Parking Lot, I am the owner and have lived up her for 12 years, it is $5 per vehicle, per day. I do provide 2 toilets, trash&recycle cans, dog waste bags, and it is a self pay set up, bring exact amount for visit. It is roughly a 3/4 mile hike from my parking lot to the glacier, rocky, but considered easy to moderate. Be carefull on the glacier in June or July, it will be mostly ice then, and kids (adults too) get scratched up wearing shorts and sleding or glissading down it. There are also rocks below the glacier to avoid as well. Plenty of fun to be had, even a lake to fish in below the glacier. I-70 west to exit 238, 9 miles up Fall River Rd., on the left side of the road, cannot miss it.
Paul