How long does it take to mail a letter from Colorado Maryland?

Colorado and Maryland are in the same country (United States), so the mailing time would depend on the specific locations within these states as well as the shipping method (regular mail, priority mail, etc.) utilized. Generally speaking, mail sent within the US can take anywhere from 1 to 5 business days to arrive using standard methods, though actual delivery times may vary based on several factors such as distance, weather conditions, and mail volume.