Former President Clinton acted within his authority when he created new national monuments during his final year in office, a federal court ruled Friday. The ruling was a victory for environmentalists and a blow for property-rights advocates and others who had challenged seven of the 15 monument designations in court. The Circuit Court of Appeals in Washington, D.C., heard two separate cases alleging that Clinton’s creation of the monuments violated both the U.S. Constitution and the 1906 Antiquities Act, which allows presidents to create monuments by proclamation. The plaintiffs argued that the act only allows for the protection of artificial objects (such as prehistoric artifacts), not of the land. The court was unconvinced, but some opponents have vowed to keep fighting — especially those of Grand Staircase-Escalante, the first and most controversial monument designated by Clinton.