Summary

Creates a six-month automatic expiration for presidential national monument designations (or until the end of the current Congress, whichever is earlier) unless Congress passes a law to extend or modify them. If Congress does not affirmatively extend or if it rejects a designation, the lands involved cannot be included in any future national monument for 25 years.

• Presidential national monument declarations would expire in six months or at the end of the then-sitting Congress unless Congress acts by statute.
• Congress must pass a law to extend or modify a monument within that period for it to remain in effect.
• If Congress rejects or does not extend a monument, the same lands cannot be designated as a national monument for 25 years.
• Amends the Antiquities Act by inserting a new time-limited subsection and shifting existing subsections.
• Increases Congress’s direct control over the permanence of monument designations.
• Creates a procedural deadline that could accelerate congressional consideration of monument actions.
• Could create legal and management uncertainty for federal agencies and local stakeholders during the provisional period.
• Applies only to monuments/reservations created under the specified Antiquities Act provisions; it does not change funding or create new programs.