Three men die in SA head-on crash

South Australia's Lincoln Highway has reopened after a head-on crash in which three men died near Whyalla.

Police say a Nissan station wagon travelling north on the highway and a semi-trailer travelling in the opposite direction collided on Thursday about 4pm about 30km north of Whyalla.

The three men in the Nissan died at the scene while the male truck driver was treated in hospital for minor injuries.

Major Crash investigators flew to the scene and the highway was closed for several hours.

It reopened at about 3am, although speed restrictions apply in the area.

The deaths bring the state's road toll to nine compared with four at the same time last year.