In its short and colorful existence, Occupy Wall Street has garnered reams of media attention, with countless stories focusing on its methods, aims, origins and mostly youthful participants.

But one question remains unanswered and largely unaddressed: How many people are actually “occupying” Wall Street, the District and other cities?

The short answer: No one knows for sure.

The longer answer: Not very many, say protesters and police officials, although the encampments have spread with lightning speed beyond their spawning ground in Lower Manhattan, where a loose coalition of protestors began assembling in Zuccotti Park near Wall Street on Sept. 17.

The difficulty in counting the demonstrators is their fluid, amorphous nature. The two D.C. encampments, for example, are in busy public places downtown — McPherson Square and Freedom Plaza on Pennsylvania Avenue NW — where passersby regularly mingle with protestors. This makes sorting out protestor and bystander difficult, said Sgt. David Schlosser of the U.S. Park Police, which has jurisdiction over the two sites.

As a rule, the National Park Service doesn’t do crowd counts; it got out of that business after the Million Man March in 1995, when its estimates fueled political controversy.

But that doesn’t mean the Park Service isn’t keeping an eye on how many Occupy protestors are turning up. Since the D.C. protest began in early October, the agency has been making periodic checks of the unpermitted group in McPherson Square to ensure that the number of people there doesn’t exceed 500, the regulated limit, said Bill Line, a Park Service spokesman.

So far, no problem: The park has been under capacity, Line said. (The Freedom Plaza group is operating with a permit that requires protestors to move when another organization has reserved the space).

There’s no question that the D.C. protests have grown since the first Occupy D.C. signs sprouted, judging simply by the number of tents pitched in both spots. But even the most optimistic estimates peg these demonstrations at levels far below the kind of rallies Washington regularly sees.

“I would guess that there are maybe 200 to 300 people sleeping here now,” said Matt Phillips, who has been in McPherson Square for the past three weeks. “It’s really kind of hard to say for sure because people come in and then go out.”

Sam Jewler, who is working on an Occupy D.C. newspaper, also couldn’t say with certainty how many were involved. The number waxes and wanes throughout the day, he said, usually peaking about 6 p.m. as people stop by after work.

The onset of winter will probably pare the number who stay around the clock, Jewler said. “But even if there are 20 to 30 of us in the park in the middle of the winter, it’s going to be enough. When spring comes, new people will join us.”

The small numbers of occupiers raise a question: Is the news media’s coverage disproportionate, magnifying a “movement” that has relatively few participants?

Numerically, the Occupy movement is similar to the early days of the antiwar movement of the 1960s, said Todd Gitlin, a Columbia University professor who has written extensively about that era. The first major antiwar protest, in April 1965, drew just 20,000 people nationwide, he said. It took several years for the antiwar marches to reach the massive levels of the late ’60s and early 1970s, when several hundred thousand people crowded the Mall.

And, after only six weeks of protests, the Occupy crowd is way ahead of those antiwar demonstrators in public support. A poll released Oct. 24 by the Pew Research Center and The Washington Post found that 39 percent of Americans said they support the protests, with 35 percent opposing them. About 80 percent of Americans opposed the antiwar movement in its earliest days, Gitlin said.

“I would go so far as to say this might be unique in American history ,” he said. “No movement, at least no movement on the left, has begun with this degree of goodwill. Certainly, no movement in the 1960s began with this degree of goodwill.”

The Occupy protestors have some way to go to achieve the numbers of the Bonus Army, the assemblage of World War I veterans and their families who camped in the District for several months in 1932 to demand cash bonuses for their service. The estimated number of participants in those protests exceeded 40,000.