When anti-conservation legislators in the House tried to thwart the creation of new national parks and monuments, perhaps they were concerned that President Obama would use his authority to shield from development environmentally sensitive areas of his native Hawaii.

No, that can't be it. Mr. Obama's predecessor, Republican President George W. Bush, used that authority in 2006 to create the 137,600-square-mile Papahanauokuakea Marine National Monument. Stretching from Hawaii to Midway, the monument encompasses more area than the all of the National Park System, combined.

Mr. Bush was one of 16 presidents - eight of each major party - to use authority under the Antiquities Act of 1906 to establish national monuments to conserve historic or environmentally sensitive lands.

The list is long and impressive Teddy Roosevelt used it first in 1906, for the Devil's Tower and Grand Canyon national monuments. Calvin Coolidge used it in 1924 for the Statue of Liberty. Jimmy Carter used it in 1978 for Denali, Alaska.

Those who shepherded the bill to diminish the presidents' designation power still haven't gotten over President Bill Clinton's 1996 designation of the Grand Staircase-Escalante, Utah national monument, which removed 2 million acres of public land from development.

A few other designations have been controversial but, overall, the law has ensured conservation of hundreds of important sites in all 50 states.

The Senate should reject the effort to diminish conservation of the nation's natural and historic heritage.