The city of Boulder is home to an active population that enjoys the outdoor opportunities in the area. Boulder is extremely popular with outdoor enthusiasts as it is surrounded by more than 36,000 acres of recreational open space, conservation easements, and nature preserves. The area is much-loved by rock climbers, mountain bikers, and hikers as well as those who enjoy winter sports.

Boulder has been named the Top Triathlon Town by Inside Triathlon magazine, one of the Most Bicycle Friendly Cities in the World by Virgin Vacations, the second Healthiest Town in the US by Men's Health, the number one Best City to Raise an Outdoor Kid by Backpacker Magazine, and has earned a number of other similar distinctions for being a healthy place to live for people of all ages.

The community of Boulder is well-known for its bicycle culture. It boasts hundreds of miles of bike paths, lanes, and routes that interconnect, creating a network of bikeways that are usable year-round. Boulder has 74 bike and pedestrian underpasses that facilitate safe travel throughout much of the city. In 2008 the city was recognized by the League of American Bicyclists as a platinum-level bicycle-friendly community. Walk and Bike Month is celebrated throughout June, and a Bike to Work Day is held each summer and winter. Mountain biking is also quite popular in and around Boulder.

There are a number of world-class hiking trails throughout the city, and the most popular area to hike is Chautauqua Park. Some trails are a short drive away, but many start at the western edge of the city. There are trails for all ages and ability levels throughout the Boulder area.

Rock climbing aficionados flock to the Boulder area for some of the nation’s best climbing routes. The primary climbing areas are Eldorado Canyon, The Flat Irons and Boulder Canyon. Boulder is also home to the Ultimate Players Association (UPA), the governing body for the sport of Ultimate Frisbee in the United States.