25 CFR §162.571

1. (a)Unless the lease provides otherwise, the lessee must notify all Indian landowners of the proposed amendment.
2. (b)The Indian landowners, or their representatives under § 162.013, must consent to an amendment of a WSR lease in the same percentages and manner as a new WSR lease under § 162.012, unless the lease:
   1. (1)Provides that individual Indian landowners are deemed to have consented if they do not object in writing to the amendment within a specified period of time following the landowners' receipt of the amendment and the lease meets the requirements of paragraph (c) of this section;
   2. (2)Authorizes one or more representatives to consent to an amendment on behalf of all Indian landowners; or
   3. (3)Designates us as the Indian landowners' representative for the purposes of consenting to an amendment.
3. (c)If the lease provides for deemed consent under paragraph (b)(1) of this section, it must require the parties to submit to us:
   1. (1)A copy of the executed amendment or other documentation of any Indian landowners' actual consent;
   2. (2)Proof of mailing of the amendment to any Indian landowners who are deemed to have consented; and
   3. (3)Any other pertinent information for review.
4. (d)Unless specifically authorized in the lease, a written power of attorney, or a court document, Indian landowners may not be deemed to have consented to, and an Indian landowner's designated representative may not negotiate or consent to, an amendment that would:
   1. (1)Reduce the payment obligations to the Indian landowners;
   2. (2)Increase or decrease the lease area;
   3. (3)Terminate or change the term of the lease; or
   4. (4)Modify dispute resolution procedures.