Utah Code § 78B-2-213: What constitutes adverse possession not under written instrument.

Land is considered to be possessed and occupied adversely by a person claiming title not founded upon a written instrument, judgment, or decree in the following cases only, where:

(1) it has been protected by a substantial enclosure;

(2) it has been usually cultivated or improved; or

(3) labor or money amounting to the sum of $5 per acre has been expended upon dams, canals, embankments, aqueducts, or otherwise for the purpose of irrigating the land.