In the usually empty urban oasis known as the Aztec Garden, behind the Organization of American States Building, five female figures, each 7 feet tall, seem to be scurrying across the path, hell-bent on getting somewhere. Their hair is flying, their jeans flap in the wind. They are not real: Their silhouettes have been cut from sheets of raw steel by Venezuelan artist Beatriz Blanco. But their crackling energy fills the garden with a welcome presence.

Blanco, 37, is one of Venezuela's best-known young artists, and she has spent the last three years in America on a grant from her government. This show, her first solo in Washington, informs us there is a strong new artist in our midst, and her concurrent show of smaller work at Zenith Gallery confirms it.

The sculptures in both shows deal with the same female figure with flying hair. But the works in the OAS garden are monumental in scale, and the artist uses the surrounding space to fine advantage. Whatever their size, however, Blanco's working method remains the same: She begins by drawing her figure on a cardboard pattern, which is then placed on a sheet of Cor-Ten steel at a foundry, and cut out. Readers of art magazines will recognize this method as one currently being used by American artist Jonathan Borofsky.

But Blanco then proceeds in one of two ways: She either removes the cut-out figure and mounts it on a base to make it free-standing; or she cuts it and arranges it at an angle to the steel sheet from which it was cut, making a sculpture that contains a pair of images--positive and negative.

A former maker of animated films, Blanco sometimes superimposes successive images to imply movement. The cutting by the founders is extremely fine, leaving intact the passages of energetic lines that Blanco uses so expressively in her drawings.

This series of work, all made since Blanco moved to Washington, is known collectively as "Presence on the Path," and it has great variety of mood within this limited format. The large sculpture will continue to offer good company to visitors in the Aztec Garden through Oct. 8. The garden can be reached by pathways either next to the OAS building at 17th Street and Constitution Avenue NW, or the Museum of Modern Art of Latin America at 201 18th St. NW. Hours are 10 to 5 every day.

The seven works in the Zenith show, at 1441 Rhode Island Ave. NW (where Blanco also has a studio), are on view through Sept. 4, Monday through Saturday, noon to 6. Also on view are the works of four other artists working in the Zenith complex--bronze sculptor Carol Newmyer and painters Ellen Sinel, Mark Shecter and Laima Simanavichus. Margery Goldberg has made a good and informative videotape to go with the show. It can be seen upon request. Sculpture at Glen Echo Park

"Earth Five," the current site-sculpture show at Glen Echo Park, is a very big idea, and gives Washington at least a taste of the kind of sculptural excitement--and experimentation--that goes on at Artpark in Lewiston, N.Y., every summer. Given the wealth of talent in this area--and the space available at Glen Echo--one wonders why we can't have that sort of ongoing program here.

But thanks to the inspiration and encouragement of Patrick Mohr, former resident sculptor at Glen Echo, six good works by five artists have sprouted in the park this summer, two of them visible from the parking lot.

Most prominent is "Life Cycles" by Margot Schnitzer de Neuhaus--four tall cedar logs encircling four split logs that lean on each other teepee-style. Though wholly abstract, the piece has anthropomorphic overtones, conjuring the image of people watching a wrestling match, or some other physical activity. The work has close-up pleasures as well. The wood has been stripped of its bark, the surfaces then gouged and carved to heighten awareness of the textural and color variations in the cedar. It is an altogether pleasing experience.

So is David Harper's environmental piece that stands nearby. Marked by a roughly built, free-standing orange doorway, the piece beckons the viewer into the woods via a path marked by a succession of door jambs of diminishing size. The reward for taking the lure: an encounter with a small brook, where the path is obstructed by a pile of natural rubble (topped by a soda can or two) that provokes all kinds of pro-environmental thoughts.

It also conjures recollections of a far more ambitious piece of the same sort shown at the 1977 Documenta exhibition in Kassel, Germany--the work of American sculptor George Trakas, who is still frustratingly absent from the Washington scene.

There are other pieces scattered around the park, including Elizabeth Follin-Jones' "The Four Elements" and Paula Daves' conceptual "Time Grid." Gathering darkness kept me from seeing them, but I did find--and enjoy--Jean Rutka's primitive, provocative "Community" tucked into a clearing behind the yurts. Consisting of sentinel-like bundles of tall sticks bound together by string and surrounding a hollowed-out ditch, the work gives off the aura of some ancient ritual or burying ground.

The show--for which Glen Echo deserves a heap of praise--continues through Sept. 30. While at the park, don't miss the opportunity to visit the Writer's Center where artists' books are both published and sold. Several of the same, wonderfully imaginative books are now on exhibit in the window of WPA's bookshop at 404 Seventh St. NW. Photograph Sale

Photography dealer Gerd Sander, who closed his gallery last winter but now deals privately, will put his entire stock of 19th-century photographs on sale today at 1430 Highland Dr. in Silver Spring from 10 to 5. Photography books, posters and catalogues as well as vintage images--some as low $10 to $50--will be included. Rain date is tomorrow, 1 to 6.