© 2004 Human Kinetics Publishers, Inc. Background: Obesity is an epidemic in the United States, yet few programs have been implemented on a widespread basis to deal with it. Colorado on the Move is a state-wide program with a specific quantifiable behavioral goal for increasing lifestyle physical activity (i.e. walking) and decreasing energy intake to prevent weight gain. Methods: A nonrandomized intervention trial designed to increase walking by 2000 steps/d using electronic step counters. Results: The intervention was effective in increasing average steps/d by at least 2000 over a 14-wk period. Conclusion: The Colorado on the Move intervention was effective in significantly increasing physical activity over a 14-wk period. Steps/d appears to be a good target for use in interventions to increase physical activity. Simply increasing physical activity in the population by 2000 steps/d could help in preventing the average yearly increase in body weight seen in the US population.