Boone, CO has a population of 351 and is the 21,613th largest city in the United States. The population density is 971 per sq mi which is 1902% higher than the Colorado average and 971% higher than the national average. The median age in Boone is 36 which is approximately equal to the Colorado average of 36. In Boone, 53% of the population over 15 years of age are married, 83% speak English and 16% speak Spanish. 76% of Boone residents were born in Colorado, 23% were born out of state, 1% were born outside of the United States and 1% were foreign born.