GRAND FORKS (AP) - There is nothing useless, junky, abandoned or trifling about the scrap metal business these days, despite how the dictionary defines scrap.

Nothing better illustrates that than the mountains of rusty and faded iron towering over and bulging into fences at the Residual Materials Inc. yard on Mill Road, on the north edge of Grand Forks. The hills are a sign of a worldwide bull market for scrap steel, copper, brass and aluminum.

In one heap 25 feet tall, a polyglot combination of aged combines - a green John Deere, red International Harvester and Massey Ferguson, a galvanized steel Gleaner - are scrunched against, over or under one another, closer than they ever fraternized in the farm fields of yore.

Another pile is hundreds of rusty wheels. Here are massive and bridgeworthy I-beams, cultivator shovels, long pipe, discs of all sizes and ex-uses.

Elsewhere in this yard lie what these scrapped steel stuff may become: cubes of metal mashed and smashed into surprisingly compact, compliant and heavy packages 2 feet by 3 feet by 4 feet, stacked along the railroad track, waiting to be shipped to furnaces somewhere in the United States, maybe St. Paul, to be remade into new steel.

Residual Materials ships much of its scrapped copper, brass and aluminum to China.

Although there has been a small summer plateau in prices, prices for scrap metals are at or near all-time highs.

It's really more than Residual Materials can handle, Dusty Gibbs said. He and his brother, Mitch, own the company; his son, Tyler, is the site manager.

"The combine pile out there is just crazy," Tyler said of the used farm harvester trade. "We've never had that many combines in here like that."

Their father, Jim Gibbs, started out 30 years ago salvaging computers and other technological equipment from missile sites across northern North Dakota.

After the Red River Valley flood of 1997, they began dealing in general scrap metal.

The growth of late has been "phenomenal," Dusty said. "When we started taking in steel after the flood, we got maybe a couple hundred tons a month."

In the past year or so, the market went nearly wild.

"We took in over 5,000 tons one month," he said. "We had no time to prepare or load. We just emptied trucks from morning till night."

Now it's regularly 3,000 tons or more.

On a recent day, Alan Watson, a farmer from Buxton, pulled into RMI's weigh station in his pickup, pulling a trailer full of the cut-up pieces of a 40-year-old John Deere corn planter.

The planter, which he used when he started farming, had been sitting in his farm yard for years, Watson said.

"This is really just a good chance to get the yard cleaned up," he said.