Colo. Rev. Stat. § 35-46-113
Partition fences between agricultural and grazing land shall be erected and also kept in repair at the joint cost of the owners of the respective adjoining tracts, except as otherwise agreed by such owners. If after thirty days written notice, served personally or by registered mail by either the owner or tenant of one tract upon the owner or tenant of the other tract, such other owner neglects or refuses to erect or repair one-half of the partition fence, the person giving notice may proceed to erect or repair the entire partition fence and collect by a civil action at law one-half the entire cost thereof from the other owner. Any judgment obtained against the owner of any land for the value of his share of any such partition fence or the repair thereof shall be a lien upon such owner's land to which such fence is appurtenant, and a special execution may issue and be levied upon the land to which such fence is appurtenant as in the manner now prescribed for the levying of an execution under the foreclosure of a mortgage upon real property. Such land may be sold under sheriff's sale for the purpose of satisfying such special execution in the same manner as is now provided for the foreclosure of mortgages on real property.
C.R.S. § 35-46-113
For foreclosure of mortgages on real property, see articles 37 to 41 of title 38 and C.R.C.P. 120.