MADISON, Wis. -- Authorities said no explosives or contraband of any kind were found inside a semitrailer truck stopped in rural western Wisconsin after the driver led a trooper on chase Thursday.

Monroe County Sheriff Dennis Pedersen said early Friday morning that authorities found only the truck's load of energy drinks after an hours-long search.

The Dane County Bomb Squad examined the truck after a police dog trained to detect explosives alerted to something in the trailer. Pedersen said he doesn't know what the dog hit on. He speculated it could possibly have been a trace of previous cargo, such as fireworks.

Pedersen said an unspecified number of homes along Highway 16 near Sparta were evacuated as a precaution. Authorities said Highway 16 was closed between Sparta and Bangor as authorities investigated the contents of the semitrailer. The FBI was assisting in the investigation.

"We fooled around in the Sparta area until about midnight, and it didn't look like we were going to go any place. We saw the bomb squad come earlier on, so we ended up getting a hotel in Sparta and spending the night in Sparta," said resident Bud Holzhousen.

The Wisconsin State Patrol said a state trooper tried to stop the 18-wheel semitrailer at about 2:20 p.m. Thursday after seeing it driving erratically, heading west on Highway 12 near Tomah. The driver sped up and continued on Highway 16, according to authorities.

Authorities said the 44-year-old truck driver is from British Columbia and lives in Ontario. Pedersen said it's not clear why the driver didn't initially stop for the trooper, but the man appears to be very sleep-deprived.

The truck is registered to PUNA Transport, out of Ontario, Canada. The owner of PUNA Transport said the driver has been working for him for three weeks without incident.

"Yeah, I checked the background, good driver, everything like that. I have checked every company he's worked in," said owner Kewal Virk.

Virk said the driver hasn't had any trouble with the law. Virk said the spoke with the driver at 5:30 a.m. Thursday after the driver picked up a load of energy drinks from Cold Spring, Minn.

Police said the driver, identified as Beant Singh Gill, is being held in the Monroe County Jail on suspicion of recklessly endangering safety and fleeing an officer. He is expected to make his first court appearance on Monday.