(a) At the time the proof of posting is filed the claimant must file in duplicate an application for patent showing that he has the possessory right to the claim, in virtue of a compliance by himself (and by his grantors, if he claims by purchase) with the mining rules, regulations, and customs of the mining district or State in which the claim lies, and with the mining laws of Congress, such statement to narrate briefly, but as clearly as possible, the facts constituting such compliance, the origin of his possession, and the basis of his claim to a patent. The application should contain a full description of the kind and character of the vein or lode and should state whether ore has been extracted therefrom; and if so, in what amount and of what value. It should also show the precise place within the limits of each of the locations embraced in the application where the vein or lode has been exposed or discovered and the width thereof. The showing in these regards should contain sufficient data to enable representatives of the Government to confirm the same by examination in the field and also enable the Bureau of Land Management to determine whether a valuable deposit of mineral actually exists within the limits of each of the locations embraced in the application.

(b) Every application for patent, based on a mining claim located after August 1, 1946, shall state whether the claimant has or has not had any direct or indirect part in the development of the atomic bomb project. The application must set forth in detail the exact nature of the claimant's participation in the project, and must also state whether as a result of such participation he acquired any confidential, official information as to the existence of deposits of uranium, thorium, or other fissionable source materials in the lands covered by his application.

(c) In applying for patent to a mining claim embracing land lying partly within one proper office and partly within another, a full set of papers must be filed in each office, except that one abstract of title and one proof of patent expenditures will be sufficient. Only one newspaper publication and one posting on the claim will be required, but proof thereof must be filed in both offices, the statements as to posting plat and notice on the claim to be signed within the respective land districts, as well, also, as all of the other statements required in mineral patent proceedings, except such as, under the law, may be signed outside of the land district wherein the land applied for is situated. Publication, payment of fees, and the purchase price of the land will be further governed by the provisions of §§1823.4(a) and 1861.2 of this chapter.