By definition Colorado Revised Statutes:

Improvement Survey Plat means a land survey plat as defined in subsection (12) of CRS 38-51-102 resulting from a monumented land survey showing the location of all structures, visible utilities, fences, hedges, or walls situated on the described parcel and within five feet of all boundaries of such parcel, any conflicting boundary evidence or visible encroachments, and all easements, underground utilities, and tunnels for which properly recorded evidence is available from the county clerk and recorder, a title insurance company, or other sources as specified on the improvement survey plat.