Colo. Rev. Stat. § 31-12-119
The landowners of any tract or contiguous tracts of land aggregating five acres or more located on a boundary of the municipality at the time of the disconnection action may, three or more years after annexation, petition for disconnection from the municipality if such municipality does not, upon demand, provide the same municipal services on the same general terms and conditions as the rest of the municipality receives. The procedure for such disconnection shall be as set forth in parts 6 and 7 of this article, insofar as consistent with this section. To the extent that such parts are inconsistent with this section, the provisions of this section shall prevail when the action is based on failure of the municipality to serve an annexed area.
C.R.S. § 31-12-119
This section is similar to former § 31-8-119 as it existed prior to 1975.