I'm not an ambitious driver, so I'd say absolutely no more than 2 hours driving time. Thanks.

hello native, within 2 hours you can reach fort collins, denver or colo. springs. or you can head straight up boulder canyon to nederland.
however you don't say how long you have in boulder or give any idea what you might be interested in seeing. also the time of year you are traveling is relevant in colo because of the snow... some roads and places are not accessible.

Rocky Mountain National Park, Cheyenne (WY), Denver, Blackhawk/Central City casinos...

Boulder, Colorado or Boulder, Nevada?????

The responses you have received assumed Boulder, Colorado.

Also assuming Boulder CO: Why would you want to leave Boulder? Just order a brew and sit out on the Mall and watch the people go by. If you like more activity, there is the new retail development at 29th Street. Or, maybe even try a trail or two. The view standing under the Flatirons is fantastic!! (unless there's smog).

Will be in Boulder, CO for 5 nights the 3rd week in June. Have been to Vail, Breckenridge and Beaver Creek. Perhaps we'll check out Nederland. Love beautiful but not really exhausting walks. (Notice I did NOT say hikes!). Galleries and little bistro-type restaurants. Don't mind some tourist-y things like Celestial Seasonings tour. Any must-sees?

For a great walk in Boulder, give the Boulder Creek trail a try. For the most scenic part start from downtown (Boulder) and walk west along Boulder Creek towards Boulder Canyon.

You might also enjoy Cherry Creek North. It's about a 45 minute drive from Boulder and has numberous galleries, restaurants, boutiques et cetera.

You really shoudn't miss a day in Estes Park and Rocky Mountain National Park. It'll be busy, but it's very scenic drive there and through the park. I would also recommend heading to Golden and checking out Red Rocks Amphitheater.

While in Boulder, definitely go to the Dushanbe Tea House for brunch.