One of Washington's biggest snowstorms in years finally eased up on the nation's capital Monday, leaving city transportation virtually shut down and city workers facing days of shoveling and plowing to clean snow-clogged streets.

Federal offices were to be closed Tuesday, and District of Columbia Mayor Anthony Williams said that would help the city cope with the snow cleanup.

Williams said there had been so much snow and ice that it could take crews as long as 60 hours to clear some side streets.

"We're going to be working around the clock on it and I'm going to be out there with them," Williams said, referring to city workers.

"They've obviously helped out quite a bit just by staying closed," he said of the federal government.

"The storm is in the last gasps as it heads toward the northeastern United States," meteorologist Andy Woodcock of the National Weather Service in Sterling, Va. said Monday.

The storm left 16.1 inches of snow at Ronald Reagan National Airport as of noon EST Monday, 24.2 inches at Dulles International Airport and 26.6 inches at Baltimore Washington International Airport, forecasters said. Different areas of the city got more than the 16.1 inches at National Airport, meaning the job of digging out would be even more difficult in some areas.

The city was last hit this hard with a 17-inch snowfall on Jan. 6, 1996. The worst snowfall ever recorded in Washington was the 28 inches that fell Jan. 27-28, 1922 which became known as "the Knickerbocker" storm because the Knickerbocker theater in downtown Washington collapsed during a performance, killing 100 people inside.

One of the mayor's major concerns was what to do with the snow cleared from the streets.

"You can't just dump it in the river. That's an environmental hazard," Williams said. City officials said they were searching for a place to move the snow and leave it.

Ed Tinsley, 22, a senior at the University of Southern California visiting Washington for the weekend, said he would be trapped in the city at least one more day after his flight home was canceled.

"It's beautiful, but honestly it seems like everyone's overreacting," Tinsley said as he wandered the mostly barren downtown streets of the city looking for a place to eat. "It's important for businesses to stay open on a day like this."

The heavy layer of snow closed most of the monuments and museums and the National Zoo.

Major airports in the area were struggling to resume service.

Ronald Reagan National Airport, Dulles International Airport in suburban Chantilly, Va., and Baltimore-Washington International Airport were not open for flights Monday morning, but workers labored to get runways open as soon as possible.

District of Columbia officials declared a snow emergency, in part to enforce parking restrictions designed to help work crews clear the streets. Similar measures were taken in the surrounding suburbs of Maryland and Virginia.

The White House scaled back Bush's public schedule on Monday -- a day after he left Camp David in the early morning to get back to Washington on snow-covered highways.

Most of the city was shut down, but the subway was operating with packed trains on a limited schedule, using only the underground portion of the system. Buses were running up to an hour late.

Shaun Quigley, 26, of Washington, dug his car out of 4-foot snowdrifts so he could get to his office at a downtown advertising agency and get ready for a business trip he might be able to make on Tuesday.

"Who knows if the train ride's going to happen," he said, "but I need to be prepared in case it does."