The concrete silos of the first US grain export depot to be built in 25 years are rising 66 miles up river from the Pacific Ocean, two mountain ranges and more than 1,500 miles away from the nation’s midwestern breadbasket.

The location is easily ex-plained: traders who historically barged most of the US grain surplus to the Gulf of Mexico now want to be closer to Asia. “China is the major driver,” says Larry Clarke, chief executive of the joint venture of commodity trader Bunge and Itochu and South Korean shipowner STX Pan Ocean that is developing the $200m (€159m, ￡133m) terminal in Washington state.

As US politicians lose sleep over the trade deficit with China and the dollar-renminbi exchange rate, American farmers are eyeing a record $14bn in exports there this year. The US had a $4bn trade surplus in agricultural products with China in the first four months of 2010, helping shave the total deficit to $71bn in the period. The relationship will be in focus today when monthly trade balance data are released.