43 U.S.C. § 322 — Desert lands defined; question how determined

This section defines "desert lands" for the group of laws it belongs to (sections 321 to 323, 325, and 327 to 329 of this title). Land counts as "desert land" if it is not timber land or mineral land, and it cannot grow any farm crop without being irrigated. To prove that a piece of land is desert land, at least two credible witnesses must swear an oath saying so, and their sworn statements — affidavits — must be filed at the local land office where the land is located. In the end, the Secretary of the Interior, or an officer the Secretary picks, decides and makes the rules for what counts as desert land.