Chestnut trees do well even in poor soil, which makes the coal field project promising, said Mr. Burhans.
The coal field around Yanzhou and Tengzhou in southern Shandong has some of the largest coal reserves in China.
The country is about to hire banks to sell global investors a stake in its giant Tavan Tolgoi coal field.
The display model here, after it was disassembled, would be put onto trucks bound for its new home, a coal field in Wyoming.
Most of the old jobs are long gone, on a steady decline since the 1940's, when coal field employment peaked at 140,000.
The research examined the subsidies given to coal production in the US's largest coal field, the Powder River Basin, and found they totalled $2.9bn£1.9bnbn) a year.
Alaska has large coal reserves at the Beluga Coal Field in south-central Alaska, about 45 miles (72 km) west of Anchorage, and in the National Petroleum Reserve Alaska.
BEIJING — Rescue workers in northern China struggled Monday to reach 153 miners trapped a day earlier when water gushed into a warren of tunnels dug for a new underground coal field.
The number of coal field workers, who earn upward of $100,000 a year including benefits, has risen by about a third since 2002, to about 2,000, according to figures from the Utah State Geological Survey.
