UPDATE (4:20 p.m.) - All lanes of Highway 227 were reopened to traffic as of 4 p.m.
Authorities say the head-on crash occurred when a white Lexus crossed over the double yellow lines and hit a green Toyota Highlander.
The driver of the Lexus was the only person in the vehicle. There were two people in the Highlander.
(3:38 p.m.) - Emergency crews are responding to a head-on crash at the intersection of Price Canyon Rd. and Highway 227 near Old Edna on Thursday.
It happened shortly after 3 p.m.
CAL FIRE SLO officials say three people are injured. Two people suffered moderate injuries and one person sustained minor injuries.
Drivers of both vehicles had to be extricated, according to authorities.
First responders say traffic is congested in the area with the southbound lane of 227 blocked, as well as part of the northbound lane. The California Highway Patrol is directing traffic around the crash, using the shoulder.
CAL FIRE SLO says two engines are on scene and ambulances are on the way.