Utah Code § 17-78-401: County powers to acquire, construct, and control roads and other facilities -- Retainage.

(1) A county may:

(a) contract for, purchase, or otherwise acquire, when necessary, rights of way for county roads over private property, and may institute proceedings for acquiring such rights of way as provided by law;

(b) lay out, construct, maintain, control, and manage county roads, sidewalks, ferries and bridges within the county, outside of cities and towns;

(c) designate the county roads to be maintained by the county within or extending through any city or town, which may not be more than three in the same direction;

(d) abolish or abandon county roads that are unnecessary for the use of the public, in the manner provided by law; and

(e) lay out, construct, maintain, control, and manage landing fields and hangars for the use of airplanes or other vehicles for aerial travel.

(2) If any payment on a contract with a private contractor to construct county roads, sidewalks, ferries, and bridges under this section is retained or withheld, the payment shall be retained or withheld and released as provided in Section 13-8-5.