The president also designated a third national monument, California Coastal, which covers thousands of small islands, rocks and reefs off the state's Pacific coast that serve as a habitat for wildlife such as sea otters and birds. And, he expanded by 8,000 acres the Pinnacles National Monument, south of San Jose, California, to better protect spire-like rock formations that rise up to 1,200 feet high.

The president emphasized that all of the land set aside Tuesday is already owned by the federal government, and that he and Babbitt received input from local citizens, state and local officials and members of Congress.

Clinton toured the Grand Canyon by helicopter Tuesday

"In managing the new monuments we will continue to work closely with the local communities," Clinton said. "This is not about locking land up, it is about freeing them up from the threat of sprawl for all Americans for all time."

Although the land covered by the proposals is owned by the U.S. government, a national monument designation bans mining, timber cutting or other large-scale development, limiting the income of many area residents involved in those industries.

The White House says the purpose of the monument designation is to protect unique natural, scientific and historic features in each of the sites.

Environmentalists have applauded the move, saying it would protect land amid the rapid expansion of the Southwest. A recent poll conducted by environmental groups indicates that more than 60 percent of area residents support Clinton's move.

Critics, including some Republican lawmakers, say the federal government has usurped congressional power and grabbed the land without local input.

"I think this is a blatant attempt by President Clinton to use the Antiquities Act for political purposes to essentially shut out the democratic process," said R.J. Smith, senior environmental scholar with the Competitive Enterprise Institute in Washington.

When the proposals were announced by Babbitt in December, Arizona Sen. John McCain, who is running for the Republican presidential nomination, said Clinton had no right to make such a move "unilaterally."

Arizona officials have urged Clinton to include state residents in any such decision, while Republican lawmakers say Clinton is using his executive privilege to bypass the GOP-led Congress.

McCain, Arizona Gov. Jane Dee Hull and other Arizona lawmakers rebuked Clinton in a joint letter for creating the two national monuments in their state.

"We join in again requesting that you forgo unilateral federal action in declaring further monuments in Arizona, and instead work with us as we involve the people of Arizona in a preservation effort that allows the public a voice in the process," said the letter, dated January 7.

George Frampton, chairman of the president's Council on Environmental Quality, wrote back and argued that the public has already had sufficient input.

Babbitt and Interior Department officials have held more than 60 meetings on the proposed Arizona monuments, including two public hearings, Frampton wrote.

Sen. Frank Murkowski, a Republican from Alaska who chairs the Senate Energy and Natural Resources Committee, has said Clinton should allow Congress to consider such moves, arguing the president should not use the Antiquities Act to unilaterally declare places national monuments.

Murkowski said recently that he might consider legislation this year to require public input in situations that did not constitute an emergency.

A spokeswoman for the committee said the Antiquities Act, created to protect lands being ravaged, was not meant to be used the way Clinton was using it.

"When it was started back under Teddy Roosevelt, they were emergency powers. We've come a long way since then," she said. "These are already public lands ... If they feel they need further protection, why not at least bring it to Congress?"

As Babbitt made his recommendations last month, he noted that all presidents since Theodore Roosevelt, except Richard Nixon, Ronald Reagan and George Bush, used their authority to protect federal lands under the Antiquities Act.

Other defenders of the act also say it has helped preserve some of the country's national -- and natural -- treasures.

"The Statue of Liberty was protected through the Antiquities Act, (as were) Devil's Tower (National Monument in Wyoming) and Acadia (National Park in Maine)," said Tom Kieran of the National Parks Conservation Association.

White House spokesman Jake Siewert said "Congress has the power to overturn it, but they never have."

Residents of Fredonia, Arizona, which is near the proposed Grand Canyon-Parashant National Monument, fear federal restrictions associated with national monument status will replace their quiet lifestyle with a hectic, tourist economy.

The mayor of Fredonia, a tiny community about 50 miles from the monument boundary, said local people resent federal mandates and are worried about effects on the ranching and timber industries. "They'll declare this monument. They'll go home, and we'll be left to take care of it," Mayor Joy Jordan said before Clinton's declaration.

"I thought we were going to have some input," Jordan said. "But things have not worked out that way at all. So I feel very sad and very helpless."

"We think it is totally disrespectful of the local community," said Mohave County Supervisor Carol Anderson, whose district covers the monument area.

But Laurent Gaudreau, a 73-year-old outdoor-gear salesman at the Canyon's South Rim, disagreed. "Once land is gone, it is gone forever," he said.

Observers say the situation represents a struggle between local governments, which often serve residents by making use of natural resources, and federal officials who want to serve all citizens by preserving those same resources.

"These two things are clashing as development is increasing," said Professor Sheldon Kamieniecki of the University of Southern California. "I think as we move into the century, that question is going to be how do you balance the two?"

Just before the last presidential election in 1996, Clinton made a similar designation at the Grand Canyon and created the Grand Staircase-Escalante National Monument in Utah.

The move angered Utah lawmakers who said it would hurt the economy and block development of a key coal mine.

But on Tuesday, Clinton urged Americans to look forward. "I know we're doing the right thing, look at the day we have," he said, gesturing toward the blue sky. "Maybe if there's one thing that unites our fractious country across parties and across generations and across time, it is the love of this land. We cannot improve upon it, as President Roosevelt said, the only thing we can do is protect it."

CNN's Jim Hill, Natalie Pawelski and Chris Black, The Associated Press and Reuters contributed to this report