Introduction: There is an urgent need to increase the physical activity in the population. Small-scale success has been achieved in programs like Colorado on the Move (COM), an obesity prevention program using electronic pedometers. Methods: To provide baseline information for COM, this first-ever statewide survey of walking was conducted with 1098 individuals. The weighted mean BMI was 25.3 ± 0.18 kg·m-2, and mean age was 44 ± 0.42 yr of age. Subjects participated in a short telephone interview and then were sent a pedometer to wear for four consecutive days. A total of 742 of the 1098 subjects completed the pedometer phase. Results: The average adult in Colorado reported taking 6804 steps per day. About 33% reported taking fewer than 5000 steps per day, and only 16% reported taking 10,000 or more steps per day. Steps per day increased with other self-reported measures of physical activity (P = 0.0001) and decreased with self-reported inactivity (P = 0.0001). Significant determinants of steps per day included increasing age (negative, P = 0.001), marital status (positive for single status, P = 0.05), income (positive for incomes of $ 25,000 to $ 99,000, P = 0.003), and increasing BMI (negative for BMI > 30 kg·m-2, P = 0.000). Obese individuals (BMI s 30 kg·m-2) walked about 2000 fewer steps per day than normal-weight individuals. These results provide the first population data on current walking levels, on how this relates to self-reported physical activity, and on determinants of walking. Results also provide a baseline level of walking for future evaluation of COM. Conclusion: Increasing steps per day appears to be a good target to use in interventions to increase physical activity. Even in Colorado, one of the leanest states, very low levels of physical activity are seen in much of the population. Copyright © 2005 by the American College of Sports Medicine.