A fire in the Raft River area that had grown to 423 acres by Tuesday afternoon was sparked Monday afternoon by a truck hauling two trailers loaded with burning straw bales, officials said. 

Idaho State Police said the fire started at 4:54 p.m. Monday when the load of straw bales, hauled by Clifton K. Robinson, 45, of West Valley, Utah, caught fire near mile marker 11 of Interstate 86. 

Clifton was driving westbound in a 2003 Peterbilt semi-truck, which set off the wildfire along the north roadside, state police said. State police did not specify how the straw ignited, but tightly packed, damp straw is known to spontaneously combust. 

The right lane of travel was blocked for approximately four hours, state police said. 

A Bureau of Land Management spokeswoman said her agency's fire crew was dispatched to the scene at 5:30 p.m. and responded with a bulldozer and two engines. She said several rural fire departments also responded. 

She said containment was estimated by 6 p.m. Tuesday and control was predicted for 6 p.m. Wednesday.