(a) Determined by ownership of land. As a general rule, and in the absence of any particular governmental purpose to be subserved, no township is eligible for resurvey unless title to at least 50 percent of the area of the lands embraced therein remains in the United States. For the purpose of determining the eligibility of a township under this rule, lands covered by approved selections, school sections, and entries upon which final certificates or patents have been issued are to be considered as alienated lands. Townships within the primary limits of railroad land grants are generally ineligible.

(b) Determined by physical character of remaining public land. In general no resurvey will be undertaken unless the preliminary examination of the township develops evidence of existing settlement and agricultural possibilities sufficient to support the presumption that the unappropriated lands therein are such as to attract bona fide entrymen, thus eliminating townships which, although theoretically eligible, are of such a physical character that the resurvey thereof would serve no useful purpose.

(c) Small areas. In the application of the terms of the Act of March 3, 1909 (35 Stat. 845), as amended, is not intended that there shall be undertaken any work involving the mere reestablishment of lost or obliterated or misplaced corners in a limited area of a township, such work being within the province of the local surveyors, and the authority of the public survey office will be limited to the giving of advice in accordance with the circular for the restoration of lost or obliterated corners. Employees of the Bureau of Land Management are prohibited from participating in the resurvey of a township, the reestablishment of lost corners, or in the subdivision of sections for private parties, even if the expense is borne by the county or municipal authorities or by individuals.