If you are required to perform assessment work and—

(a) You fail to perform the assessment work as required in this part, your claim is open to relocation by a rival claimant as if no location had ever been made; or

(b) You fail substantially to perform the assessment work as required in this part and the land is withdrawn from mineral entry or the mineral for which the claim was located is no longer subject to the Mining Law, BLM may declare your claim forfeited.