D.C.'s Inauguration Head Count: 1.8 Million

First, although some experts described it as high, the official estimate released by the District yesterday is 1.8 million, a figure that would make the gathering the largest ever on the Mall.

Second, from space we look like ants.

Authorities for years have been wary of estimating crowd sizes for events on the Mall, but numbers poured forth yesterday -- including from D.C. Mayor Adrian M. Fenty's office.

In radio interviews, Fenty (D) cited the 1.8 million figure, which eclipses the 1.2 million official tally from the 1965 inauguration of Lyndon Johnson.

Mafara Hobson, Fenty's spokeswoman, described the count as a "collective decision" reached Tuesday inside the city's joint operations command center, where dozens of local and federal agencies were helping to coordinate security and traffic management. She said it was based on information collected by several cameras and individuals on the ground.

"The 1.8 [million] was communicated out to the mayor's office and other agencies," she said.

The National Park Service, which has been barred from making estimates since its count of 400,000 at the 1995 Million Man March drew the threat of a lawsuit, issued a statement yesterday saying it would "not contest" the 1.8 million estimate.

"We do firmly believe that the crowd that was there was the biggest crowd ever, and I think that's what people are most interested in," Park Service spokesman David Barna said. "We don't have anything that suggests there was ever a bigger crowd."

But three experts arrived at lower estimates after viewing a satellite image of the event. Steve Doig, a journalism professor at Arizona State University, estimated that 750,000 people were on the Mall and in the ticketed areas near the Capitol, excluding the parade route and city streets.

There are caveats: The satellite image was taken at 11:19 a.m., 45 minutes before the swearing-in. At the time, spectators were still gathering.

Also, the image does not capture the thousands of people who were sheltering in museums or walking through the Third Street tunnel. Shadows compound the difficulty of counting people on city streets.