43 C.F.R. § 3835.91
What if I fail to file annual FLPMA documents?
If you fail to file an annual FLPMA document by December 30, as required in § 3835.31(d), you forfeit the affected mining claims or sites.
If you fail to file an annual FLPMA document by December 30, as required in § 3835.31(d), you forfeit the affected mining claims or sites.