One direction of a major highway in western Hennepin County was closed well into the afternoon Thursday because of a diesel fuel spill blamed on a drowsy truck driver, officials said.

The location of the spill was Hwy. 12 between May Street and Baker Park Road, near Long Lake, according to the Minnesota Department of Transportation (MnDOT).

The spill occurred about 7:50 a.m. It was cleaned up by midafternoon, allowing all lanes to reopen, said MnDOT spokesman Nick Carpenter.

The fuel came from a westbound dump truck that hit the center median after the driver fell asleep, said State Patrol Lt. Tiffani Schweigart.

The cleanup also slowed eastbound traffic, Schweigart said.