Milky Way Planner has pages for 17 dark sky places in Colorado: 11 parks and 6 communities. Their Bortle classes run from 2 to 5. Each page has the Bortle class, the best months for the Milky Way and a free visibility calendar.
Park · Bortle 4
Park · Bortle 4
Community · Bortle 2
Park · Bortle 2
Park · Bortle 2
Park · Bortle 5
Park · Bortle 2
Park · Bortle 4
Park · Bortle 4
Park · Bortle 2
Park · Bortle 4
Community · Bortle 2
Community · Bortle 2
Community · Bortle 4
Community · Bortle 2
Park · Bortle 2
Community · Bortle 4