Gregg LeFevre, whose paper and bronze reliefs are on exhibit at the National Academy of Sciences through Jan. 15, sculpts mountains and valleys, rivers and sandbars, not as we are accustomed to seeing them -- stretching away toward the horizon -- but as we might see them through the window of a small plane. And with good reason. LeFevre flew before he walked.

"My mother was a Women's American Service Pilot (WASP)," he explains in his Boston-area studio, "and she took me flying with her from the time I was born."

It took more than 25 years, however, for LeFevre's appreciation of aerial landscapes to manifest itself in his work. He started in the early 1970s with abstract, minimal works, as his large sculptures at Boston University and the State University of New York at Cobleskill testify. "I began to get bored with minimalism," he says. "Less is more up to a point, and then less becomes less."

Several years later, he began taking low-altitude aerial photographs and experimenting with corrugated cardboard -- staining and thickening, then tearing away at the layers to get the weathered look of sediment, of sandbars, islands and peninsulas. "It was a subtractive kind of art," he says. "The secret was deciding when to stop." From there he moved on to making paper pieces from molds (two of these are in the National Academy's exhibition) and clay reliefs, which he later cast into bronze. Eventually he took his clay to the rocks themselves, made plastic impressions and cast it with white paper pulp or bronze. The last step is painting.

"The pieces become a new kind of object," he says, "something that is neither a painting or a piece of sculpture, that isn't a copy of the landscape but some new vision of it."