Mysterious Substances, Different Reactions

ON WEDNESDAY, a man walked into the Wilson Building downtown, threw a white substance at a security guard, and then ran off. The seat of the District's government was evacuated for about two hours. Authorities determined the substance was probably just harmless table salt. It was the kind of incident that has cropped up now and again after the anthrax attacks of 2001 made mysterious substances in office buildings something to fear.

But what if someone throws a suspicious bright blue material, like the stuff pictured above, on the ground? Would that spark the same kind of reaction from authorities?

That depends on where you are.

While running along Rock Creek between Woodley Park and Georgetown's Montrose Park two Saturdays back, a jogger carrying a canvas bag tossed an azure-colored granular material in a splattered pile on the ground next to a tree. He sped past an older man and this writer, then, moments later, tossed another batch of the blue stuff on a log.

His splotchy calling cards were part of a trail of markings, complete with "X" and circle designs (see map, No. 1), that wound its way through the park.

The path led to the end of Lovers Lane (see map, No. 2) near the entrance to Dumbarton Oaks Park. Once there, an arrow pointed toward a steep, rough trail uphill to Montrose Park, and then onward to R and 32nd streets NW (see map No. 3), where a circle of blue sat on the sidewalk outside Harvard University's Dumbarton Oaks Museum and Gardens. That appeared to be the end of the trail.

Was this a sinister act? It's hard to tell for sure — we didn't run any scientific tests on the stuff he left behind. It does, of course, stand to reason that a runner leaving behind a substance marking a trail was probably chalking a trail for other runners to follow.

But who knows? Just five blocks to the west — at 37th Street (see map, No. 4) — was the spot where double agent Aldrich Ames would mark a mailbox with chalk to signal his Soviet handlers he had information to exchange at the designated secret rendezvous point. Somtimes simple chalk isn't so simple.

And an interesting side note: We found a similar blue circle, pictured at right, in the West End on 20th Street NW between L and M streets (see map No. 5). It also apparently caught the attention of a gaggle of birds.

So what was going on? Bill Line, spokesman for the National Park Service's National Capital Region said that the substance was indeed probably chalk used to mark a training course for runners, and that it's not the first time that such splotches have appeared on trails through Rock Creek Park and elsewhere.

"The National Park Service does not encourage it, but we don't have any specific regulations governing it," said Line.

Generally, Line said, chalk isn't a major worry because it washes away in the rain or blows off in the wind fairly quickly. But there are areas of the city were chalking will raise the ire of federal security officials.

Under the Commemorative Works Act, it is unlawful to use chalk or other substances on monuments and memorials. And Line said that if anyone were to slap down some chalk at, say, the Lincoln Memorial, the U.S. Park Police would step in to stop them.

Those rules don't apply to other federal-controlled land, like Rock Creek Park or Dupont Circle's rotary park, where sidewalks are often chalked by various activist causes. "We don't encourage it, but we aren't going to stop it," Line said.

Photos and map by Michael Grass/Express