Under the government shutdown that began early today, the Washington Monument will close and the doors of the Smithsonian Museums and the animal houses at the National Zoo will shut.

"Anything that can be closed or locked will be closed or locked," National Park Service spokesman George Berklacy said.

Hikers trying to find their way around the Shenandoah National Park, tourists wanting a look at the Statue of Liberty and visitors to the Mall in Washington will be among the first to feel the effects of the government's budget crisis.

The stalemate comes during the Columbus Day weekend, which cushions the blow of a federal shutdown until Tuesday, department and agency officials noted yesterday.

Still, the wait-and-see game, played for the second time in a week, has become a pinching irritant for federal workers and their supervisors trying to plan for all the last-minute scenarios that have become possibilities.

"Every government worker should call in sick Tuesday just as a protest," said Eric Lindberg, 39, a Navy engineer in Crystal City. "Just to let them know that they're jerking us around too much. Things like this are definitely going to drive people out of the government."

Office of Management and Budget Director Richard G. Darman yesterday issued a memorandum to department and agency heads instructing all weekend personnel to report to work "for the sole purpose of engaging in orderly shutdown activities." Only essential personnel will remain at work during the three-day weekend.

If the budget problems are not resolved by Tuesday, all employees are to report to work then anyway, according to OMB. If no stopgap spending measure has been signed into law, nonessential personnel can expect to be sent home within the first three hours of the day.

Government officials were also ordered in the memo to prepare for the possibility of across-the-board spending cuts, which could be mandated by the Gramm-Rudman-Hollings deficit-reduction law.

Under the law, the administration would be required to reduce spending by 32.5 percent in non-exempt programs, and most of the 1.1 million federal employees who received furlough notices last month could expect to be furloughed. But the automatic cuts are predicated on the government having money to spend. Bush's failure to sign the spending bill takes away this option.

Most agency officials said yesterday that because their staffs are so small on the weekend anyway, they planned to operate as usual during the next three days.

White House press secretary Marlin Fitzwater said last night that essential services to protect health and safety would continue, as would all funding necessary for Operation Desert Shield in the Persian Gulf. But a statement from Bush read by Fitzwater said that cleanup of toxic waste sites would be halted, Social Security offices would not accept new applications and border inspections will be delayed.

The Federal Aviation Administration said last night that it had clearance to operate the air traffic control system normally through the holiday weekend. National Weather Service forecasters also will remain on the job.

It is the public playgrounds in Washington, the things that visitors and residents like to think of as escapes from partisan politics, that will be immediately drawn into the fray.

At the National Zoo, the gorilla, panda, elephant, giraffe and small mammal houses will be closed, as will the reptile and bat exhibits, the education building and the main restaurant. Zoo employees yesterday were working to figure out a way to keep the zoo's gates open so visitors will still be able to walk around outside. Zoo officials said they would not know until today if they will be able to do that.

The animals "would probably notice the daily pattern is not what it normally is," said Robert Hoage, zoo spokesman and formerly a primatologist. "If they do feel lonely, the gorillas, the elephants, the giraffes could all go outside" where the visitors might be.

Under the shutdown, the Smithsonian's 13 museums in Washington and two in New York will be closed, as will the Arlington Cemetery tour and Arlington House. Interpretive services at the Lincoln Memorial and other outdoor monuments will not be available. There will be no rangers at the Vietnam Veterans Memorial.

John F. Jameson, assistant secretary for administration at the Smithsonian, said the Columbus Day weekend is a popular one for tourists, and for residents who come out in the nice weather because they know the summer crowds have gone.

He said the Smithsonian hoped to find volunteers to stand outside its museums and explain to visitors why the drab "closed" signs are up. "It's just simply to explain to folks out of town who are less versed in the budget crisis," he said.

Outside Washington, the national parks will be without interpretive rangers, who give nature talks, pass out literature and perform other visitor services. Entrance booths will be unmanned, meaning that park visitors can enter without paying fees, according to the Interior Department. Similarly, national wildlife refuges run by Interior's U.S. Fish and Wildlife Service will be left largely unattended.

The last time the government shut down for budget reasons was on Oct. 17, 1986, when about 500,000 employees were sent home for several hours. The employees were paid retroactively when a budget was finally passed.

The House civil service subcommittee that studied a similar Nov. 23, 1981, shutdown found that the government spent $5.5 million to send workers home that day and eventually paid them the $9 million they would have earned had they been on the job.

Staff writers Robert F. Howe, John Lancaster and Don Phillips contributed to this report.