In 1987, the state legislature made changes to annexation law limiting municipal annexations to no more than three miles beyond the current municipal boundary in any given year. Further, municipalities in Colorado are required to prepare and adopt a three-mile plan prior to annexing property into their territorial boundaries per Colorado Revised Statute 31-12-105 et. seq. The three-mile plan is a long-range plan that outlines where municipalities intend to annex property and describes how they will ensure the adequate provision of services within the newly annexed territory and the remainder of the existing municipality.
