BILLINGS, Mont. (AP) - Thousands of bees were taken to a bee yard northeast of here after the semi tractor-trailer transporting them from North Dakota to California overturned on Interstate 94.

The Montana Highway Patrol said about 2,000 of the bees got loose when the tractor-trailer crashed Tuesday afternoon in the interstate's westbound lanes near the Huntley exit. The cargo consisted of nearly 13.7 million bees in 465 hives.

Trooper Dell Aman said the rig veered into a ditch and rolled, landing on its side in a ravine. Driver Robert Esper, 66, of Winnemucca, Nev., was extricated from the cab and escaped injury.

Aman said Esper wasn't speeding but drove off the road "for an inexplicable reason." He received a careless-driving citation.

Most of the bees stayed in their hives, but a "couple thousand" got loose and "wandered around the area," said Aman, adding he was stung twice at the scene. The loose bees returned to the hives later Tuesday, he said.

The hives taken to the Huntley bee yard, on the trailer that had been transporting them, remained at the yard Wednesday pending arrangements for their handling, said Scott Hanser of Hanser's automotive and towing business in Billings. The truck that had been pulling the trailer Tuesday was at Hanser's for an evaluation, Hanser said.

Aman said being stung left him with no ill effects.

"The public was in no way in danger, as long as they didn't stop to get out of their vehicles," he said. "If they did get out, they figured out pretty quickly that that wasn't the place to be - no pun intended."

Aman said an area bee expert and several hobbyists garbed in bee suits were at the scene to help as crews worked to remove the truck from the ravine Tuesday night. He said he was told that the bees that did escape would return to their hives later in the night as the weather cooled.

"The temperature dropped about 10 degrees while I was there, and they started going home," he said.

Aman said it appeared the truck would need some maintenance so the hives may need to be loaded into another truck to continue their journey.