Colo. Rev. Stat. § 30-28-108
A county or regional planning commission may adopt the county or regional master plan as a whole by a single resolution or, as the work of making the whole master plan progresses, may adopt parts thereof, any such part to correspond generally with one or more of the functional subdivisions of the subject matter which may be included in the plan. The commission may amend, extend, or add to the plan or carry any part of it into greater detail from time to time. The adoption of the plan or any part, amendment, extension, or addition shall be by resolution carried by the affirmative votes of not less than a majority of the entire membership of the commission. The resolution shall refer expressly to the maps and descriptive matter intended by the commission to form the whole or part of the plan. The action taken shall be recorded on the map and descriptive matter by the identifying signature of the secretary of the commission.
C.R.S. § 30-28-108