Find ideas below for the states of Colorado, Idaho, Utah, Montana, and Wyoming. (For AZ, NM, NV, see "Southwest US".) Both mountain and non-mountain vacation ideas are included!
Just so you know... The Rockies span 3000 miles from Canada to New Mexico, with dozens of ranges, some higher, some lower, and known by names like The Tetons in WY, The Sawtooths (ID) the Wasatch Range in Utah. You might've been in the Rockies without knowing it!
Colorado has some of the biggest names in ski resorts, such as Aspen (actually "Aspen Snowmass", with four mountain areas, and celebrity status for decades). Steamboat Springs, Crested Butte, Breckenridge... Colorado has many ski resorts, and often you'll find a quaint former mining town. All ski resorts these days have kids programs and plenty for families; look for teen programs, kids' centers, and baby care, too.
Family farms, guest ranches, and dude ranches make great getaways, with horseback riding and other fun activities, kids programs at many places, and pricing that includes meals. Kids love to imagine the cowboy way of life, and Colorado provides a great mountain setting.
Book early for this top spot for family vacations! YMCA of the Rockies has two centers in Colorado-- Snow Mountain Ranch (5100 acres) and Estes Park Center (860 acres); guests stay in lodges or cabins and can enjoy a bonanza of recreational activities, from indoor sports to family zip line, High Challenge Course, archery horse-riding, and lots more. Affordable pricing; seasonal events such as Fall Fest.
Yellowstone National Park (in Wyoming and Montana) is one of those famously popular destinations that exceeds expectations; no wonder so many people flock to it. Unique in the world, The Park contains the Yellowstone "caldera", or "Yellowstone supervolcano", which causes its amazing geothermal features (hot springs, geysers, other-worldly "terraces"). Yellowstone also has wildlife viewing, including wolves, moose, and grizzly bear, and wonderful historic inns.
"Family Adventures" are escorted tours with all-details-handled and tip-top itineraries. Read a review of a Yellowstone Family Adventure (by Austin-Lehman Tours) that included wildlife viewing with a naturalist, hiking the Grand Canyon of the Yellowstone, and (outside the Park) horse-riding and white-water rafting.
Utah has some choice spots for snow vacations, including seven different mountains right by Salt Lake City, and two more resorts under an hour from the SLC airport. Key points include Great Snow (motto is "The Greatest Snow on Earth" is the motto), and Fast Track to the Slopes: dozens of cities have direct flights to SLC, and from the airport you can reach nine different mountains in under an hour.
Whitewater rafting is a thrilling experience that crosses age barriers: it's great fun for parents, teens, preteens; and if you're on the right Class of river -- all rivers are classified by the same system-- even young kids can enjoy the ride. Keep in mind that your experience varies with the season: rivers are highest when the mountain snow is melting; late in the summer, you'll get less white-water.
Ski resorts work hard to entice visitors in summer months. For example, here's some of the summer fun at Winter Park (the closest ski resort to Denver): mini-golf, human maze, bungee, climbing wall, 3000-foot Alpine Slide, train from Denver, and more.
Vista Verde is a dude ranch near Steamboat Springs ski resort that puts out the welcome mat during the holidays. Winter fun include cross-country skiing, snowshoeing, horseriding, sleigh-rides; programs for kids and teens; off-ranch activities such as dog-sledding. Special holiday activities
include going out on cross country skis to cut a Christmas tree, making homemade decorations, go caroling, Christmas Day Feast.