SOME OF the most spectacular scenery in the world lies in southern Utah, a wonderland of rust-red rock shaped by channels of cool water, punctuated by craggy buttes and Native American ruins and artifacts. After Wednesday, more of this priceless landscape will be formally protected — if, that is, the country’s incoming Republican leaders do not allow anger at President Obama to impair their judgment.

The White House announced Wednesday that Mr. Obama designated 1.35 million acres of breathtaking lands — known as Bears Ears, after two buttes that jut prominently into the air — a national monument. The designation caps a presidential term that saw conversion of several natural and culturally significant areas into protected zones, achievements that may turn out to be the most persistent element of Mr. Obama’s legacy.

Utah leaders responded with fury, arguing that the president is behaving imperiously, and promised to push for a rollback. In fact, Mr. Obama took a moderate approach, and his critics should take a deep breath.

The president did not set aside as much land as he plausibly could have — and much less than a coalition of local tribes asked him to. The lines he drew hew more closely to those Utah officials proposed previously. Some nearby people who make their living off the land worry about their livelihoods. Yet the president’s order allows locals who currently use the area to graze their livestock or extract minerals to keep their resource privileges.

Mr. Obama’s action also was hardly a usurpation of Congress’s prerogatives, despite some of the overheated rhetoric from the president’s critics. He used powers Congress duly designated to the White House under the Antiquities Act. It is hardly unprecedented for presidents to use this power to set aside large chunks of land or sea. Legal challenges nevertheless seem likely, based on the act’s stipulation that national monuments should only be as large as is necessary to protect the treasures in question. Yet, in the case of Bears Ears and many other monuments, much of the point is to preserve sprawling, unspoiled landscape — not just a few archaeological sites.

Moreover, it is hard to blame Mr. Obama for using Antiquities Act authorities after Congress failed to consider its own conservation proposal. Time is a factor: Looters and tourists have marred precious archaeological sites in the area, despite wide agreement that they should be preserved.

There is no place quite like it. Its beauty and cultural significance deserve better than petty, partisan fights. Congress can and should still have its say: Lawmakers should write protections for the area specifically into the law, insulating them from legal challenge. But any reasonable legislative proposal would end up looking a lot like what Mr. Obama has already done. Further federal action cannot become a back-door ploy to significantly erode the protections already extended.