Updated Thursday, June 18, 2015
The Nevada Highway Patrol said it closed down the ramp on northbound Interstate 15 connecting to U.S. Highway 95 after the incident was reported about 3:20 a.m. Thursday.
"Diesel is very slippery. It's like ice, really," said Nevada Highway Patrol Trooper Loy Hixson.
No mail was damaged and the road reopened around 9 a.m.
Authorities said the driver of the semi was going about 50 miles per hour and headed to Tonopah when he realized he was entering the wrong off-ramp.
He attempted to veer off back into the flow of traffic but stopped on the ramp after the fuel tank was damaged by a barrier.
The driver stopped the truck on an incline and the fuel spilled over all lanes and the shoulder.
The driver suffered minor injuries and authorities said he will face a misdemeanor citation. He has not been named.
Hixson said the spill spanned about 1,500 square feet and would cost about $10,000 to clean up.
In Nevada, those responsible for hazardous material spills must arrange and pay for the cleanup through a private company. Officials with the highway patrol and Nevada Department of Transportation monitor the scene to ensure proper clean up. It wasn't immediately clear whether the truck was owned the U.S. Postal Service.
The cleanup will involve spreading a fine pebble-like absorbent, which is then swept away.
Authorities said the process may be hampered by Las Vegas' triple digit heat on the sizzling asphalt, as it may affect the texture of the absorbent.