; (2) make recommendations for revisions to the management plan; and (3) not later than 180 days after the date of receipt of a proposed revision to the management plan, approve or disapprove the proposed revision. (e) Amendments The Secretary shall review and approve or disapprove each amendment to the management plan that the Secretary determines may substantially alter the purposes of the Heritage Area. (f) Effect of inaction If the Secretary does not approve or disapprove a management plan or a revision or change to a management plan by the date that is 180 days after the date on which the management plan or revision or change to the management plan is submitted, the management plan, revision, or change shall be considered to have been approved by the Secretary. 5. Authorities and duties of the Caddo Lake Heritage Area Commission (a) Authorities For purposes of preparing and carrying out the management plan, the Caddo Lake Heritage Area Commission may— (1) make grants to— (A) political jurisdictions of the States; (B) nonprofit organizations; and (C) other persons or entities located in the Heritage Area; (2) enter into cooperative agreements with, or provide technical assistance to— (A) political jurisdictions of the States; (B) nonprofit organizations; (C) the heads of Federal agencies; and (D) other interested persons or entities; (3) hire and compensate staff who have demonstrated expertise in the fields of— (A) cultural, natural, and historical resources conservation; (B) economic and community development; (C) forestry; or (D) heritage planning; (4) obtain money or services from any source, including any money or services provided under any other Federal program or law, in which case the Federal share of the cost of any activity carried out using Federal funds shall be not more than 50 percent; (5) contract for goods or services; and (6) support activities of partners and any other activities that— (A) further the purposes of the Heritage Area