AUGUSTA – The use of explosives in Maine has nearly tripled over the last decade, a shift that points to the depletion of easily developed land in a state where stone often lies right beneath the soil.

According to the U.S. Geological Survey, Maine’s consumption of explosives increased from 518 metric tons in 1994 to 1,480 metric tons in 2003.

“We’ve basically developed all of the easy ground,” said Lon Santis of the Institute of Makers of Explosives. “The only patches of land we have left to develop are the difficult ones. And what makes them difficult is rock.”

Even small subdivisions now require the use of explosives to clear the land for development, said Bill Purington, president of Maine Drilling and Blasting in Gardiner.

And small buildings signal the same growth as mammoth structures.

“A lot of it is going into economic growth in the state,” he said.

Major road projects including the Big Dig in Boston and the widening of the southern leg of the Maine Turnpike also may have contributed to the increase, as Maine gravel and concrete businesses helped fill demand those projects created.