Lyons is a Statutory Town in Boulder County, Colorado, United States. The town population was 2,209 at the 2020 United States Census, up from 2,033 at the 2010 United States Census. Lyons is located at the confluence of North St. Vrain Creek and South St. Vrain Creek, 20 miles east of Rocky Mountain National Park. Due to its location at the intersection of State Highway 7 and U.S. Highway 36 which lead to Rocky Mountain National Park, it is sometimes referred to as "The Double Gateway to the Rockies".