High Quality Content by WIKIPEDIA articles! The Town of Granby is a Statutory Town that is the most populous town in Grand County, Colorado, United States. Granby is situated along U.S. Highway 40 in Middle Park about 85 miles (137 km) west of Denver, Colorado, southwest of Rocky Mountain National Park. According to the population finder off the Census Bureau`s website, in 2009, the town had a total population of 1,663.