An outdoor muralist like Byron Peck, who has covered nearly a football field's worth of Washington area walls with paint, knows the many hazards that await his art. Sun, smog and rain may rub it out. A developer's wrecking ball may smash the masonry and concrete that serve as his canvas.

To combat mural mortality, the man who painted Duke Ellington brooding over U Street NW uses long-lasting, $160-a-gallon pigment, and he creates some of his works on removable panels in case a building is condemned for redevelopment.

He keeps a list of potential sites for new murals that have a chance of surviving 10 years, but he says they're getting harder to find in Washington's development boom.

"If it's a flat wall, the way development is going now, it's going to be replaced," he says.

Now there's a new effort to document the nearly 100 examples in Washington of this inherently ephemeral art. What once may have seemed like whimsical, temporary bursts of color are being recognized as glimpses into the local soul, oversized billboards of neighborhoods' ambitions, fantasies and realities that ought to be preserved.

Before too many works are lost, a determined historian of American culture named Perry Frank is recording the wall art for posterity.

"The murals are part of the art collection of the city," says Barbara Franco, executive director of the Historical Society of Washington, D.C.

"They are a statement of community," says George Koch, co-president of the A. Salon artists cooperative. "It's like putting up a flag. They are a snapshot of ourselves as our communities change and evolve."

Murals such as Marilyn Monroe swooning over Connecticut Avenue and Abraham Lincoln splitting rails above 10th Street NW have become city landmarks, but tucked down alleys and around corners are unexpected surprises.

The history of Latin Americans is limned on the brick wall of an obscure courtyard in Columbia Heights, while the saga of African Americans is splashed over a block of Nannie Helen Burroughs Avenue NE.

The eventual yuppie invasion of Adams-Morgan is imaginatively foretold in a 25-year-old neighborhood scene--complete with scheming developers--on a cracked wall of an alley between a Chinese restaurant and a gas station on Calvert Street NW.

A fine specimen by artist Alexander Mattison on H Street NE, showing heroes of black history behind the words "For My People," was destroyed in August when the wall upon which it was painted was demolished to make way for a shopping center.

With photographer Bruce Preston and colleague Susie McFadden-Resper, historian Frank has located, photographed and catalogued about 80 murals across the city, with several more to go. She has videotaped oral histories with the artists and organized symposiums on the art of the big picture. Her collection will be housed at the Historical Society.

"I started with a list of 22 murals that I knew about," says Frank. It was probably the same list of prominent murals on the busiest streets that many residents recognize. Frank was surprised and delighted at how many more there are.

Most were created in the past 25 years, funded by the city or landowners. In a typical case, a skilled muralist such as Jorge Somarriba will enlist assistants paid through the city's summer youth program. In that sense, mural making in Washington harks back to the great government-subsidized Depression murals of the 1930s that put artists to work and forged the modern wall art tradition in this country.

A mural renaissance is underway in many cities as local boosters realize they are good for tourism. Philadelphia is a leader, with a $300,000 mural budget matched by $300,000 in donations. The city sponsored 144 new murals last year and offers guided tours.

The District will spend about $100,000 this year on new murals, says Matt Radford, a program officer with the D.C. Commission on the Arts and Humanities.

One of the oldest mural-making collectives in Washington is Sign of the Times. It organized the creation of giant portraits of 12 noted African Americans on a blank wall of the East River Park shopping center at Benning Road and Minnesota Avenue NE.

"This is another way for us to keep our history alive, since we don't control the media," says James Greggs, an administrator of Sign of the Times.

Presenting overt, uplifting social messages is popular, but another class of murals celebrates art for art's sake.

Carl Daniel let some graffiti-influenced artists decorate the big exterior wall of Call Carl Watch and TV Repair store at Georgia Avenue and Harvard Street NW. He has forgotten the artists' names, and he remains puzzled by what they wrought, but the work is much admired by mural aficionados. It shows a broken wall revealing a formal staircase and columns reminiscent of the inside of a federal building, with what look like three-dimensional graffiti letters lying about in piles.

"It celebrates the coolness of Washington," ventures Preston, the photographer. "It's clearly Washington, but it's cool."

In forsaking galleries, and the few square feet of posterity they guarantee a painter, muralists take their chances on the fickle streets. The compensation is massive surface area. "I just like seeing big stuff," Peck says.

And there's a mass audience for muralists with a message. A fading mid-1970s mural by artists from the Centro de Arte, important pioneers of Washington mural art, is on the wall of an alley off Calvert Street NW. The scene of life in Adams-Morgan includes some predatory figures playing cards. These are the real estate speculators who were remaking the neighborhood for more affluent residents, according to Frank and Carlos Arrien, a former director of the Centro de Arte.

On the occasion of the 500th anniversary of Columbus's "discovery" of America, Arrien painted "America Discovers Itself" in a courtyard on Irving Street NW near 15th Street. Through allegory and symbol, the wall portrays pre-Columbian culture and the subsequent blending and building of Spanish and indigenous heritages.

Like his fellow mural-makers, Arrien wanted to speak to people who don't visit galleries. "The idea," he says, "was to bring to the streets that people walk every day this richness and history."

Some Washington Murals

* "River Terrace." Artist Cheryl Foster and her teenage mural assistants painted huge portraits of neighborhood residents on an industrial wall just off Benning Road NE near Kenilworth Avenue.

* "Deanwood." Artist Rik Freeman tells the history of African Americans through vignettes of celebrities and regular people along Nannie Helen Bourroughs Avenue NE.

* "Air Shaft." Artist Val Lewton dressed up the Metro air shaft at H and Third streets NW with a skewed image of the Capitol and the illusion that you can see through the hulking concrete.

* "The Dignity of Work." Artist Al Smith led a team to paint a wall on W Street SE at Martin Luther King Jr. Boulevard in Anacostia, showing different kinds of labor.

* "Tribute to Life." One of a series of murals artist Jorge Somarriba designed on the long wall of Klingle Road at Adams Mill Road NW.