43 CFR 3833.22 - How do I amend my location?
(a) You must record an amended location certificate or notice with BLM within 90 days after you record the amended notice or certificate in the local recording office. BLM will not recognize any amendment to your mining claim until you file it properly.
(b) You must pay a processing fee for each claim or site you amend. See the table of fees and service charges in § 3830.21 of this chapter.
(c) An amended location notice or certificate relates back to the original location date. The amendment takes effect when you record it with the local recording office under state law or such other time as provided by state law.