25 CFR §166.229

1. (a)We must approve an amendment, assignment, subpermit, or mortgage with the written consent of the parties to the permit in the same manner that the permit was approved, and the consent of the sureties.
2. (b)Indian landowners may designate in writing one or more of their co-owners or representatives to negotiate and/or agree to amendments on their behalf.
   1. (1)The designated landowner or representative may:
      1. (i)Negotiate or agree to amendments; and
      2. (ii)Consent to or approve other items as necessary.
   2. (2)The designated landowner or representative may not:
      1. (i)Negotiate or agree to amendments that reduce the grazing rental payments payable to the other Indian landowners; or
      2. (ii)Terminate the permit or modify the term of the permit.
3. (c)We may approve a permit for tribal land to individual members of a tribe which contains a provision permitting the assignment of the permit by the permittee or the lender without our approval when a lending institution or an agency of the United States:
   1. (1)Accepts the interest in the permit (leasehold) as security for the loan; and
   2. (2)Obtains the interest in the permit (leasehold) through foreclosure or otherwise.
4. (d)We will revise the grazing capacity and modify the permit.